Zhao Alexandre

Contractual PhD Zhao Huang
email: zhao.huang@u-pem.fr

Dr. Pr Amos David

may come     China's government and companies' strategic communications and grass-roots lobbying strategies in Africa in the digital age: a case study on China's Confucius Institutes

Introduction

Taking part in the EUPRERA PhD seminar at the early beginning of the second year, my objectives are: -to make sure that my research is meaningful outside the French academic context in terms of theoretical scope. -I have experienced difficulties putting together references from political, communication and management, anthropology sciences and in limiting myself. Advices are then welcome so as to my "ambitious" corpus as my adviser says; -Since studying lobbying and influence processes is so complex and still taboo, I believe I would benefit from methodological discussions and advices on my questionnaires, interview guidelines, relation with the interviewees.

What is exactly strategic communication? What does it mean for different publics and scholars, within different disciplinary backgrounds and national contexts? If we look at a country as a unit of observation, does the strategic communication relate to a country's foreign policy and its soft power actions? It's difficult to define the concept of strategic communication, not only because it is an emergent concept, but also because "influencing people is hard" (Paul, 2012, p. 188) and influence processes are complex, and have to do with what goes on behind the political scenes. However, Chinese government efforts in this area seem to be successful, especially in Africa. Our thesis focuses appropriately on China's strategic communication mediated by the Confucius Institutes in Africa, particularly in Kenya and South Africa. It intends to analyse changing Chinese soft power and influence strategies in the digital and social media age. We rely on the perspective of "strategic communication" and "public diplomacy" combined with a "soft power" approach to highlight our first hypothesis: how China uses cultural tools as well as media and social media framing effects, especially its African-based media and social media, to build a "good" image in Africa. The meaning of "good" image remains to be defined: an environment where and strategic communication. A short note of my first exploratory survey at Tianjin Normal University in China will also be introduced, according to the new findings while the survey, our research questions and problem focused will also been be renewed at the end of this paper.

Method

In terms of methodology, we did a literature review progressing to be achieved. It principally focuses on strategic communication [START_REF] Arcos | Public relations strategic intelligence: Intelligence analysis, communication and influence[END_REF][START_REF] Argenti | The Strategic Communication Imperative[END_REF][START_REF] Eyre | Shaping the zeitgeist: Influencing social processes as the center of gravity for strategic communications in the twenty-first century[END_REF][START_REF] Hillsdale | Furnishing the Edifice: Ongoing Research on Public Relations As a Strategic Management Function[END_REF][START_REF] Hallahan | Defining Strategic Communication[END_REF][START_REF] Huyghe | Stratégies étatiques face aux enjeux de l'information[END_REF][START_REF] Paul | Strategic communication: origins, concepts, and current debates[END_REF][START_REF] Preciado-Hoyos | The strategic orientation of communications consulting firms in Colombia[END_REF][START_REF] Thomas | An introduction to strategic communication[END_REF], public diplomacy and "new public diplomacy" [START_REF] Ang | Cultural diplomacy: beyond the national interest?[END_REF][START_REF] Dutta-Bergman | U.S. Public Diplomacy in the Middle East: A Critical Cultural Approach[END_REF][START_REF] Fitzpatrick | Advancing the New Public Diplomacy: A Public Relations Perspective[END_REF][START_REF] Kiousis | Public Trust or Mistrust? Perceptions of Media Credibility in the Information Age[END_REF][START_REF] L'etang | Public Relations: Critical Debates and Contemporary Practice[END_REF][START_REF] Melissen | The new public diplomacy: soft power in international relations[END_REF][START_REF] Signitzer | Public diplomacy: A specific governmental public relations function[END_REF], Chinese soft power and nation brand building across Confucius Institute [START_REF] Anholt | Nation Branding in Asia[END_REF][START_REF] Chan | Confucius and the Curate's Egg: The Morality of China in Africa a review by Keith Somerville[END_REF][START_REF] Delisle | Soft power in a hard place: China, Taiwan, Cross-Strait relations and US policy[END_REF][START_REF] Edney | Soft Power and the Chinese Propaganda System[END_REF][START_REF] Gudjonsson | Nation branding[END_REF][START_REF] Hubbert | Ambiguous States: Confucius Institutes and Chinese Soft Power in the U.S. Classroom[END_REF][START_REF] Huyghe | Soft power : l'apprenti sorcier[END_REF][START_REF] Keohane | Power and Interdependence in the Information Age[END_REF][START_REF] Martel | Vers un « soft power » à la française[END_REF][START_REF] Noya | The symbolic power of nations[END_REF][START_REF] Nye | Bound To Lead: The Changing Nature Of American Power[END_REF][START_REF] Nye | Think Again: Soft Power[END_REF][START_REF] Papadopoulos | Place branding: Evolution, meaning and implications[END_REF][START_REF] Schmidt | China's Confucius Institutes and the 'Necessary White Body[END_REF][START_REF] Sun | Mission Impossible? Soft Power, Communication Capacity, and the Globalization of Chinese Media[END_REF][START_REF] Sun | The Chinese-Language Press in Australia: A Preliminary Scoping Study[END_REF][START_REF] Wang | Zuowei Guojia Shili de Wenhua: Ruan Quanli (Culture as national strength: soft power)[END_REF][START_REF] Zanardi | China's soft power with Chinese characteristics: the cases of Confucius Institutes and Chinese naval diplomacy[END_REF]. Our aim is to combine British, American, French and Chinese points of views in order to prefect our vision of strategic communication with an approach of soft power applied in New Public Diplomacy. As Fitzpatrick claims, all practice of public diplomacy has primarily strategic dimensions (Fitzpatrick, 2007, p. 199). In order to analyse the concept of strategy, some of competitive intelligence theories will also be studied so that the conception of strategic communication could be exhaustively outlined.

Furthermore, according to the theoretical framework, the ongoing field study will evaluate our research questions and hypothesis with empirical observation in China and Africa. As confirmed by Jan Melissen, in foreign relations: "international actors believe more and more that they are necessitated to engage in dialogue with foreign audiences as a condition of success in foreign policy" (Fitzpatrick, 2007, p. 187;Melissen, 2008, p. 14). In this situation, the model of Tchakhotine (1939) of "Receiver passive" is not in case anymore, the "two-way" models of public relations advanced by Grunig and Hunt (1984) will help us to study how Chinese government mobilizes its cultural institutions and their staff to influence foreign audiences and exercise "international advocacy." In China, firstly, we have already questioned some trainers of Hanban at Tianjin Normal University in this Summer time, we have obtained some interesting findings during this exploratory survey. These discoveries make us rethink the research's questions, China's soft power through its cultural diplomacy is nowadays richer and more complex than we expected. In our first survey in Tianjin, Wang, the senior trainer of Confucius Institute, confirmed principal missions of CI's teachers: "First of all, our mission is to spread the Chinese culture and to teach Chinese through the Confucius Institutes. Secondly, many teachers are "volunteers", they are unified training through the assignment to other countries, they are the bridge of Chinese culture communication; again, teachers establish the friendship with their foreign students to enhance mutual understanding" (exploratory interview with Wang, 18/07/2017). Yuan, CI's teacher based in Nairobi, listed to us how they build a personal relationship with their students: "We hold regularly some activities, such as making dumplings, transcultural parties, visiting some exhibitions, these activities can not only deepen students' understanding of Chinese culture, but also we can establish and develop friendship with the students" (exploratory interview with Yuan, 18/07/2017). According to these new data, we have mean to integrate in our research the less-reknown Chinese practice of "personal diplomacy".

At the next step, we plan to make more semi-directive interviews with some Chinese as a Foreign Language (CFL) teachers, CFL trainers, pedagogical specialists on CFL, organizers of international cultural activities, PR practitioners, "ChinAfrican" communication officers in Hanban (Confucius Institute Headquarters) and its collaborators. We consider them as Chinese governmental communication actors and China's "civil" diplomates who influence their audiences with strategic processes: create interpersonal relations, diffuse information in a "soft-way", receive and analyze audiences' feedback and modify their communication processes. This first empirical study will help us to clarify the organizational resources of Confucius Institute, its place in Chinese new public diplomacy strategy, and also the strategic/tactic tools used in its external communication process. Next step, in Africa, we schedule to visit local Confucius Institute in Kenya and South Africa. Interviews with CFL teachers (Chinese & foreigner teachers), CI's local leaders and CI's students will be fulfilled. We also intend to question culture/communication officers in Chinese Embassies, PR practitioners and journalists in local-based Chinese media and other local journalists. A semio-discoursive analysis was planned to analyze the development of Confucius Institutes in Africa (programs, publications, advertisements, etc.) in the traditional media and on social media, especially in the mobile application "Confucius Institute". This empirical information will help us understand the Chinese strategic communication and its new public diplomacy plan in Africa.

Theoretical framework

• Strategic communication It is challenging to find a consensual definition on strategic communication (Paul, 2011, p. 3). It is an emergent and hybrid concept, because of the variety of strategic communication activities and its multi-level dimension: companies, NGOs, think tanks, universities and public institutions. On the one hand, at the government level, strategic communication was broadly defined as "programs and activities deliberately aimed at communicating and engaging with intended audiences" (The White House, 2010) within the two fields of public affairs and diplomacy:

1) Coordinating words and deeds, including the active consideration of how one country's actions and policies will be interpreted by public audiences as an organic part of decision-making, is an important task. 2) Has a wide range of programs and activities deliberately focused on understanding, engaging, informing, influencing, and communicating with people through public affairs and public diplomacy. (The White House, 2010, p. 2) The concept of strategic communication has also been mentioned in the trade literature as a way to describe organisation's global public relations' actions, so to say "the planned and organised effort of a company, institution, or government to establish mutually beneficial relations with the publics of other nations" (Wilcox, Cameron, & Reber, 2014, p. 545). [START_REF] Hillsdale | Furnishing the Edifice: Ongoing Research on Public Relations As a Strategic Management Function[END_REF] interprets strategic communication from a public relation's viewpoint as a "bridging activity" (p. 171) between organizations that should be institutionalized (Thomas & Stephens, 2015, p. 4). In practice, it encompasses "coordinated actions, messages, images, and other forms of signalling or engagement intended to inform, influence, or persuade target audiences in support of national objectives" (Paul, 2011, p. 3). Farwell, according to him, the strategic communication is as an influential practice which is based on "the use of words, actions, images, or symbols to change the attitudes and opinions of target audiences to shape their behaviour in order to advance interests or policies, or to achieve objectives" (Arcos, 2016, p. 265;Farwell, 2012, pp. xviii-xix).

On the other hand, strategic communication was broadly defined as communication activities that allows organizations to reach their objectives (Hallahan et al., 2007, pp. 3-4;Preciado-Hoyos et al., 2017, p. 3). Strategic communication was then described as "aligned with the company's overall strategy, to enhance its strategic positioning" [START_REF] Argenti | The Strategic Communication Imperative[END_REF]. In the French academic field, strategic communication (communication stratégique) is known to be a fresh concept related to "public diplomacy" [START_REF] Huyghe | Soft power : l'apprenti sorcier[END_REF]Pahlavi, 2015, pp. 553-606) and is seen as the toolbox for diplomacy [START_REF] Reynaud | Discours sur la RSE dans le processus de légitimation de la banque, Discourse on CSR in the legitimacy process in the banking sector[END_REF]. French war studies' academic researcher, François-Bernard Huyghe built a theoretical framework that relates competitive intelligence to strategic communication [START_REF] Huyghe | Vie et mort d'une discipline: la polémologie[END_REF]. He pointed out five aspects of strategic communication: a fortress strategy to prevent information breaches to keep high-value information secure; a strategy based on propaganda and believes as key factors of mobilization; a strategy based on image framing through the worldwide promotion of a given cultural model more basically said of a given way of life. His framework also strengthens the importance of "channels" both new and old: propaganda flyers and real-TV shows shouldn't be underestimated in the digital age. Then it focuses on attention rather than on access or profusion of messages. A wise use of wording can help any community manager improve the page-rank of his blog-posts and being on top of page-rank means better chances to drive the public attention. An activist who enjoys the support of a community may manage to drive its attention. A Mister nobody who spends a lot of time on forums (BBS) may also manage to catch the public attention (Huyghe, 2010, pp. 103-108).

• Soft Power and Public Diplomacy

The search for power is, according to many observers, a structuring determinant of international life (Wintgens, 2015, p. 19), because "power is seen as the ability to get others to do what they otherwise would not do" (Nye, 1991, pp. 25-26). Inspired by the Hobbesian concept of the lawless state of nature where human being competes each every [START_REF] Braillard | Théories des relations internationales[END_REF][START_REF] Grieco | Anarchy and the Limits of Cooperation: A Realist Critique of the Newest Liberal Institutionalism[END_REF]Paul, Wirtz, & Fortmann, 2004, pp. 29-51;Walt, 1998, pp. 29-35), the realists maintain that nations are the main actors on the international stage. The world is understood as anarchic, which means that international relations are the result of violent power relations (hard power) which involve the implementation of military, human and material resources (Gallarotti, 2015, p. 248;[START_REF] Nye | Soft Power[END_REF], but also financial and economic sanctions.

Because of economic integration and the trend of internationalisation, more and more common interests had appeared for international stakeholders, so that the cooperation has become an alternative paradigm of realism (Braillard & Djalili, 2016, p. 16). The neoliberalism and constructivism recognise international politics as "socially constructed", the nucleus of constructivism indicates that: "1) The structures of human association are determined primarily by shared ideas rather than material forces, 2) The identities and interests of purposive actors are constructed by these shared ideas rather than given by nature" (Wendt, 1999, p. 1). In fact, the neoliberal institutionalist theory has firstly developed by [START_REF] Keohane | Power and interdependence: world politics in transition[END_REF], they discovered the increasing international connections, particularly in economy and culture, while the decline of power balancing and military force. Based on this finding, they have highlighted the importance of "soft power" which could help a state to "get the outcomes you want without tangible threats or payoffs" (Nye, 2004, p. 5).

As the confirmation of Eyre and Littleton (2012, p. 180), "the term 'whole-ofgovernment approach' with its emphasis on integrating "hard" and "soft" power, is no longer a neologism." The development of "soft power" ends the "Carrot and Stick policy" era on foreign policy, and is now generally acknowledged as a key resource of power. Seen as the "second face" (Bachrach & Baratz, 1962, pp. 947-952) of power, the soft power emphases the importance of social connection and is defined as a state's national ability which uses and mobilises different immaterial resources, such as culture and art, for captivating, communicating and persuading target audiences in the reaching established goals. Keohane and Nye explain the stated objectives of soft power are "get desired outcomes because others want what you want, on the other hand, to achieve desired outcomes through attraction rather than coercion" (Keohane & Nye, 2012, p. 216).

In French academic field, the concept of soft power joins in the "influential diplomacy" (diplomatie d'influence) [START_REF] Martel | Vers un « soft power » à la française[END_REF][START_REF] Tenzer | La diplomatie d'influence sert-elle à quelque chose ?[END_REF] which represents one country's "referential" [START_REF] Muller | Référentiel. Références[END_REF] in its participation of international communication. Culture and knowledge encapsulate values, ideologies and beliefs and represent important resources of "soft power" [START_REF] Desmoulins | La diplomatie parallèle des think tanks français internationalistes : les propriétés capacitantes de l'hybridité organisationnelle[END_REF][START_REF] Gupta | Soft Power of the United States, China, and India: A Comparative Analysis[END_REF][START_REF] Martel | Vers un « soft power » à la française[END_REF][START_REF] Delisle | Soft power in a hard place: China, Taiwan, Cross-Strait relations and US policy[END_REF][START_REF] Courmont | Chine, la grande séduction : Essai sur le soft power chinois[END_REF][START_REF] Bläser | Socio-spatial opportunities and the power of place -Bankwatch-NGOs in Washington, D.C[END_REF][START_REF] Keohane | Power and Interdependence in the Information Age[END_REF][START_REF] Nye | Think Again: Soft Power[END_REF][START_REF] Nye | Soft power: the means to success in world politics (1st ed)[END_REF][START_REF] Nye | Bound To Lead: The Changing Nature Of American Power[END_REF]. In agreement with Huyghe's viewpoint, emphasizing on soft power could solve "4I problem" -image, influence, ideology, interest (Huyghe, 2011, p. 85). By enhancing a country's worldwide image and by spreading its ideology, soft power activities work in favour of a country's national interest as well as for the interests of its elites and flagship top national companies.

The concept of "soft power" has been enthusiastically integrated and largely studied in China. As the ability to "influence others though agenda setting, attraction or co-option" (Nye, 2004, p. 8), soft power was first introduced in 1993 in China by Wang Huning, a senior Chinese Communist Party official (H. [START_REF] Wang | Zuowei Guojia Shili de Wenhua: Ruan Quanli (Culture as national strength: soft power)[END_REF]. Soft power has become the core power of Chinese "Peace and development" foreign policy. Chinese political and diplomatic scholars also found the similarity between Nye's soft power and Chinese intellectual value, in Dao De Jing, Chinese Taoist founder, Lao Zi has explained that "in this world below the sky, the gentle will outdo the strong. And the non-material is able to enter the impregnable. Thus I know and know for sure the gains that under-acting yields. But teaching by the word unspoken in this world few can master; The gains that under-acting yields in this world few realize (Stanza 43)" (Roberts & Laozi, 2001, p. 118) . Chinese character "rou" (soft) was translated as "gentle" which refers to water, in Laozi's viewpoint, the strongest power is to be "gentle", just like attractive power which could gradually convince people without conflict and hurt.

However, Chinese perspectives on soft power still have some different arguments. Zheng and Zhang have discussed on Nye's conceptual framework between soft and hard power was "too simple", and they argued that a part of Nye's discussions on soft power is somewhat "not scientific enough" (often used Chinese rhetoric) (Lahtinen, 2015, p. 6) which divorced from the reality of international politics and, they claim Nye's examples of soft power, like American TV shows , "pop" culture, film industry and international entertainment development "do not have important implications for international politics" as long as "sovereign states are still the major players in international relations, and national interests are still the most important factor they consider when formulating foreign policy" (Zheng & Zhang, 2012, pp. 25-26), as a result, they have concluded that "whether a power resource is soft or hard depends on the feelings and perceptions of various actors in specific situations" (Zheng & Zhang, 2012, p. 21), so that the main actors of soft power could be a country, a government, a political party, an interest group, a social class, etc.

In the eyes of many Chinese scholars, the Western misunderstanding of China and the popular "Chinese threat" debate come from the lack of understanding of the Chinese core cultural value (Lai, 2012, p. 85).That is why Chinese researchers take the "culture" as the essence of soft power. Like CPC senior official Wang Huning argued: "if a country has an admirable culture and ideological system, other states will tend to follow it.(…) it does not have to use its hard power which is expensive and less efficient" (Lahtinen, 2015, p. 7;[START_REF] Wang | Zuowei Guojia Shili de Wenhua: Ruan Quanli (Culture as national strength: soft power)[END_REF]. In fact, the scope of Chinese use of soft power idea is wider than other countries. The "soft power with Chinese characters" (H. [START_REF] Wang | Zuowei Guojia Shili de Wenhua: Ruan Quanli (Culture as national strength: soft power)[END_REF] includes diplomatic exercises and domestic politic activities. Different from many countries which use their Popculture (like United States), film industry (like the USA, South Korea, India), tourism resources (like France, Span) and political model as the most important part of soft power, the scope of China's soft power is focused on its traditional culture, long history, economic development model, multi-industrial cooperation, and the construction of "international circle of friends" (Guoji Pengyouquan: Chinese language rhetoric from Xi Jinping's discourses, that means an international network of relationship).

In practice, increasing soft power is often inseparable from the development of one country's public diplomacy. As an evolving concept, public diplomacy is not as clear and widely recognized as soft power on definition. One of large quoted definitions is proposed by Tuch: "a government's process of communicating with foreign publics in an attempt to bring about understanding for its nation's ideas and ideals, its institutions and culture, as well as its national goals and policies" (Tuch, 1990, p. 3). It's also widely defined as a main tool to win over the 'hearts and minds' of foreign audiences, and to persuade them that they all have and approve the same values, goals and desires (van Ham, 2008, p. 48). In a communication perspective, public diplomacy is "the art of communicating with foreign publics to influence international perceptions, attitudes and policies" (Waller, 2007, p. 19). Yet, French theoreticians point out "two revolutionary impulses" of public diplomacy which are the decisive role of public opinion and the use of new communication technologies [START_REF] Balzacq | Traité de relations internationales[END_REF]Pahlavi, 2015, pp. 553-565).

Indeed, after 9-11, a rising of researchers began to think the tie between public diplomacy, political theories, international relations theories and public relations theories with communication models and practices [START_REF] Dutta-Bergman | U.S. Public Diplomacy in the Middle East: A Critical Cultural Approach[END_REF][START_REF] Fitzpatrick | Public relations and public diplomacy: Conceptual and practical connections[END_REF][START_REF] Kruckeberg | Public relations, not propaganda, for US public diplomacy in a post-9/11 world: Challenges and opportunities[END_REF]. Jan Melissen's remarks, firstly, that the public diplomacy is no longer seen as "left-overs of diplomatic dialogue", and secondly, the public diplomacy will no more be considered as "an attempt at manipulation of foreign publics" (Melissen, 2008, p. 11).

Based on the public relations approach, Melissen indicates the concept of "New" public diplomacy which is not simply for promoting a country's policies to foreign audiences, it's also an operation relies on "building relationships with civil society actors in other countries and about facilitating networks between non-governmental parties at home and aboard.(…)In order to safeguard their interests in a globalized world, countries need 'permanent friends' in other nations" (Fitzpatrick, 2007, p. 188;Melissen, 2008, pp. 22-23).

Even though public diplomacy is not a current term presented in China, but the Chinese version of "cultural diplomacy", which is an essential instrument of China's foreign policy and soft power, that has already shown the shadow of "new public diplomacy" emphasised by Melissen. Chinese scholars have also outlined the blueprint of China's "culture diplomacy": "promoting traditional culture and value and acting as a responsible great power on the world stage; advocating a harmonious world and peaceful rise; demonstrating the virtues of the Chinese path of economic development; expanding its foreign assistance; and developing own discourse in world affairs"(Y. Wang, 2006, pp. 134-140) ; In addition, the increasing of Chinese "personal diplomacy" at the elite level is another component of its new public diplomacy, which relies on people-to-people exchanges, scholarships, bilateral and multilateral cultural programs and increasing contacts, leads to build the "high level of trust" (Yu, 2009, pp. 10-11, 18) and mutual understanding, especially in the developing and less developed countries.

To sum up, it seems that, as an important instrument of one country's soft power, public diplomacy has already become an international relation practice based on dialogue and respect for mutual values and designed to promote and develop trans-cultural understanding [START_REF] Dutta-Bergman | U.S. Public Diplomacy in the Middle East: A Critical Cultural Approach[END_REF][START_REF] Fitzpatrick | Public relations and public diplomacy: Conceptual and practical connections[END_REF]. Public diplomacy has also engaged in establishing connections between different cultures, developing interactions and dialogue, and participating in a process of mutual sharing of meanings between each culture [START_REF] Grunig | Excellence in public relations and communication management[END_REF][START_REF] Kent | Toward a dialogic theory of public relations[END_REF]. The strategic actions, behind all of one state's public diplomacy motivations, have been also highlighted [START_REF] Habermas | Théorie de l'agir communicationnel (Vols 1-2)[END_REF]. In the observation of Signitzer and Wamser, public relations and public diplomacy are both "strategic communication functions and process of either organisations or nations-states" (Signitzer & Wamser, 2010, pp. 41-43).

To conclude, strategic communication could help pushing a particular point or more generally it may take part in the promotion of a country's culture and national interest in the long term. Strategic communication also encompasses the tightening of durable personal relationships with important people through both elite-level and grass-roots-level exchanges (Edney, 2012, p. 902;Nye, 2004, pp. 108-110).

• Strategic Dimensions

The practice of new public diplomacy as a process of strategic communication. In fact, all practice of public diplomacy, whatever traditional, contemporary or so-called "new" public diplomacy, includes at least three dimensions: connecting with information or knowledge, practicing communication and bringing influence, and political participation. The concept of "strategy" has been defined by lots of research fields, but its common sense focuses on the conscious action "in development of building the future decisions" (Arcos, 2016, p. 1;Mintzberg, 1978, p. 935). This could lead to a series of guidelines or to standardize operating procedures (SOP), as "patterns in a stream of decisions" (Mintzberg, 1978, p. 935;Mintzberg, Raisinghani, & Théorêt, 1976, pp. 246-275). In the "strategy-as-practice" approach, scholars point out the relations between "discourses" and practices. Discourses are indeed performative (Austin, 1962, p. 4) in international relations. Strategic intelligence deals with "actions, interactions and negotiations of multiple actors and the situated practices that they draw upon in accomplishing that activity" (Thomas & Stephens, 2015, p. 4;Jarzabkowski, Balogun, & Seidl, 2007, p. 8). If we define strategic communication through "soft power" lenses, strategic communication becomes a "soft" kind of political communication, that relies on methods such as storytelling, psyops, spin doctors, nation branding, or perception management [START_REF] Huyghe | Soft power : l'apprenti sorcier[END_REF]. However, before the "work-out" of strategic communication for a state's public diplomacy action, the research, collection and analysis of information should be firstly considered in the decision-making process.

The PRSA (Public Relations Society of America) defines PR as "a strategic communication process that builds mutually beneficial relationships between organisations and their publics" (Wilcox et al., 2014, p. 33). Its cyclical process often described as RACE (Research, Action, Communication, Evaluation) [START_REF] Marston | The Nature of Public Relations[END_REF] or ROPE (Research, Objectives, Programming, Evaluation) [START_REF] Hayes | Public relations cases (9th ed)[END_REF]. The "research" and "analyse" are taking a key place for the strategic communication achievement. Because the "research provides useful intelligence" like a "central source of information on the organization, the public's image, the industry or field, and the social, economic, and political trends" (Cutlip, Center, & Broom, 2005, p. 113).

In the competitive intelligence frame of reference, "precise knowledge of self and precise knowledge of the threat leads to victory" [START_REF] Charles | L'art de la guerre[END_REF], getting intelligence and collecting all useful information contribute to diagnose the main problem and the potential risk. If we put the management concept of "absorptive capacity" [START_REF] Cohen | Absorptive Capacity: A New Perspective on Learning and Innovation[END_REF] in the international relations situation, it should represent an organisation's ability to recognize different values, assimilate and exploit new information (or knowledge) for its political, social, and cultural purposes. Indeed, the strategic communication activity related to public diplomacy depends on three different elements of soft power: strategic resources, strategic capacity, and strategic programming [START_REF] Huang | L'entrelacement des figures du public chinois des musées français présents sur les médias sociaux chinois : entre diplomatie culturelle et communication stratégique[END_REF].

First, strategic resources refer to tangible and intangible heritages and resources. An internal audit and external information monitoring facilitate a global understanding of all resources and the management of knowledge which could be mobilised in future diplomatic campaign. Second, strategic capacity links knowledge and communication channels. [START_REF] Desmoulins | La diplomatie parallèle des think tanks français internationalistes : les propriétés capacitantes de l'hybridité organisationnelle[END_REF] identify the soft power as a relational form of power and mention that "no matter how poorly gifted a country is as regards to energy resources, it can be powerful if it is well integrated in international organizations and transnational academics of think tank networks", the soft power still benefits from a "framing power of media" (Bläser, 2005, p. 289). Furthermore, the strategic programming corresponds to a tool box of communication actions for the diplomatic operation. These three elements also conform to the operational process of competitive intelligence analysis: objective defining, information monitoring, data analysis, strategic reactions and information diffusion [START_REF] Desmoulins | De la RMA à la guerre infocentrée : retours d'expérience sur les promesses inaccomplies de la numérisation et du big data[END_REF].

Research questions:

In this paper, we aim to analyse Chinese strategic communication dealing with the creation and development of Confucius Institutes focusing on Confucius Institute activities.

According to our theoretical framework, the field work has begin in the summer of 2017 and will be continued until the end of 2018. We have selected Kenya and South Africa as the focus of the study area. In the summer of 2017, we visited at Tianjin Normal University which established the Confucius Institute in Nairobi, Kenya, as the first African branch of Confucius Institute. During our exploratory survey with the head of International Exchange Institute and some trainers of Confucius institute, we have remarked that China's Confucius Institutes do not only use education and culture as their communication and international influence tools for reaching their cultural diplomacy, but also they do mobilize their own national media, African local media and social media as an essential platform for diplomatic operations. The people-to-people diplomacy has already developed form elite level to the grass-roots level. With these new findings, we have divided our following research questions and field work into five parts: RQ1. The background of so-called Chinese cultural diplomacy. In this part, what is the background of Chinese renewed strategic communication? What is China's strategic communication seeks at the cultural diplomacy level, even at the new public diplomacy level? As Chinese soft power focuses not only on diplomatic exercises, but also on its domestic policy, will China's domestic media control policy be reflected in its cultural diplomacy? What are the history and the current situation as regards to Chinese propaganda? What are the doctrinal texts that shape China's soft power strategy?

RQ2. What is China's "media" strategy whereas frontier in between the public and the private cannot be drawn? What are Chinese media in Africa and media and IT companies? What are the "pipelines" for China's diplomacy and strategic communication (Confucius Institutes, local universities, local media, etc.)? How these "pipelines" work together for Chinese diplomatic purpose?

RQ3. What are the organizational resources and the strategic communication related activities (networking, etc.) of the Confucius Institutes? In practice, how does China's government labels and promotes Confucius Institutes? How Chinese government (through Confucius Institute and its institutional partners) mobilizes its communicational tools to promote a given, a desirable vision of Chinese culture in Africa? How does the Chinese government train its Confucius Institutes' teachers to take part in China's strategic communication? What's the role of Chinese teachers in Confucius Institute?

RQ4. Provocatively, we want to end up with a question on Confucius. Why Confucius after all? What is left of the Confucian thinking in the Confucius Institute activities? How and why does China promote a given vision of "Confucius" as a philosopher, thinker on everything from art de vivre to lobbying, yet a precise culture, a prophet or a label? RQ5. Chinese people-to-people diplomacy and Chinese concept of "Guanxi" (in English: Relationship). What is the definition of Chinese practice of "personal diplomacy" in the scheme of its public diplomacy? In Chinese perspective, what is the meaning of "Guanxi"? What was the key role played by "Guanxi" in China's society? How Confucius Institutes exercise people-to-people diplomacy in their educational and communicational agenda? What is the relation enclosed by the concept of "Guanxi" and "two-way" model of communication? What is the connection bounded by "Guanxi", "public diplomacy" and "public relations", "win-win" business partnership? In people-to-people diplomacy that Chinese governmental institution carries out, what are the contacts and distinctions between relation-building strategies and informational/grass-roots lobbying strategies?

The thesis will examine the current logic of China's strategic communication through the narrow prism of China's Confucius Institutes. It is based on the concepts of soft power and grass roots lobbying. The main research question is: Is there anything special aspect in China's strategic communication? What are the many different activities that take place at Confucius Institutes or thanks to Confucius Institutes? How do these activities take part in China's strategic communication? How are they promoted by African-based media and social media, to build a "good" image of China in Africa?

In short, this study is about China's cultural presence in Africa, we want to use strategic communication as an analytical framework to tackle Chinese soft power and grassroots lobbying strategies. Our study encompasses the communication actions of China's national educational institute -Confucius Institutes in Africa by focusing on two main countries: Kenya and South Africa.

During the EUPRERA PhD seminar, we are waiting for your remarks and feedback on our theoretical framework concerning the mix of strategic communication, soft power and (new) public diplomacy. According to you, which part has to be improved? What kinds of other concepts have to be considered? Furthermore, we hope that you can give us some advice on the field work strategy. In fact, we are planning to achieve our field work in Africa between February and April 2018. We are wandering how can we get more useful information during our empirical research? And what kind of survey methods could be more practical and effective in public relations research? We really would like to exchange all of these questions with you.


Solène Comby-Dassonneville

Fabien Volpi
email: fabien.volpi@simap.grenoble-inp.fr

Marc Verdier

Electrically-functionalised nanoindenter

Keywords: Functional nanoindentation, Local capacitance measurement, Stray capacitance, Quantitative data-processing Highlights:

come

Introduction

The development of small-scale characterisation techniques of dielectric structures has become increasingly critical for various application fields: micro-and nano-electronics [START_REF] Williams | Two dimensional dopant profiling by scanning capacitance microscopy[END_REF][START_REF] Pingree | Nanoscale Impedance Microscopy -A characterization tool for nanoelectronic devices and circuits[END_REF], electronics [START_REF] Shao | Local impedance imaging and spectroscopy of polycrystalline ZnO using contact atomic force microscopy[END_REF], electrochemistry [START_REF] Layson | Resistance measurements at the nanoscale: scanning probe ac impedance spectroscopy[END_REF][START_REF] O'hayre | Frequency-dependent transport imaging by scanning probe microscopy[END_REF], photovoltaics [START_REF] Jiang | Imaging charge carriers in potential-induced degradation defects of c-Si solar cells by scanning capacitance microscopy[END_REF], biological science [START_REF] Biagi | Nanoscale electric permittivity of single bacterial cells at gigahertz frequencies by scanning microwave microscopy[END_REF],… Traditionally this can be achieved through the coupling of Atomic Force Microscopes (AFM) [START_REF] Binnig | Atomic force microscopy[END_REF] to capacitance sensors (or more generally to impedance-meters [START_REF] Kopanski | Scanning capacitance microscopy for electrical characterization of semiconductors and dielectrics IN[END_REF][START_REF] Zielinski | Application of different modes of nanoscale impedance microscopy in materials research[END_REF]). After the pioneering work of Matey and Blanc [START_REF] Matey | Scanning capacitance microscopy[END_REF], the early Scanning Capacitance Microscopes (SCM) that combined AFM to capacitive measurements were dedicated to surface topography mapping [START_REF] Bugg | Scanning capacitance microscopy[END_REF][START_REF] Williams | Scanning capacitance microscopy on a 25 nm scale[END_REF]. These set-ups have then been extended to the profiling of dopant distribution in semiconductors [START_REF] Williams | Two dimensional dopant profiling by scanning capacitance microscopy[END_REF][START_REF] Williams | Lateral dopant profiling on a 100 nm scale by scanning capacitance microscopy[END_REF][START_REF] Kopanski | Scanning capacitance microscopy applied to two dimensional dopant profiling of semiconductors[END_REF][START_REF] Edwards | Scanning capacitance spectroscopy: An analytical technique for pnjunction delineation in Si devices[END_REF], which remains the major application for SCM. In these systems, the capacitance sensor is an inductancecapacitance-resistance (LCR) resonator operating at ultra-high frequency (usually 915 MHz) coupled to a peak detection circuit. The tip-to-sample capacitance being part of the LCR circuit, any change in its value is sensed from a change in resonance, further related to dopant concentration. Even though SCM is currently applied to the characterisation of Metal-Insulator-Semiconductor (MIS) structures, this technique does not apply to dielectric film characterisation as there is no voltage-dependent depletion in such materials. A pioneering attempt [START_REF] Asami | The scanning dielectric microscope[END_REF] to perform permittivity and alternating conductivity measurements on dielectric materials was spatially-limited by the large scale probe (circa 100 µm). Nanoscale Impedance Microscopy (NIM) has then been developed to characterize frequency-dependent charge transport and polarization mechanisms in dielectric films [START_REF] Shao | Local impedance imaging and spectroscopy of polycrystalline ZnO using contact atomic force microscopy[END_REF][START_REF] Layson | Resistance measurements at the nanoscale: scanning probe ac impedance spectroscopy[END_REF][START_REF] Zielinski | Application of different modes of nanoscale impedance microscopy in materials research[END_REF][START_REF] O'hayre | Quantitative impedance measurement using atomic force microscopy[END_REF][START_REF] Pingree | Bridge-enhanced nanoscale impedance microscopy[END_REF][START_REF] Wu | Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy[END_REF]. Contrary to SCM, the NIM technique provides the measurement of both resistance and capacitance of the tip-to-sample interface: both the amplitude and phase of the current induced by an alternating bias are measured.

However one of the main limitations for the quantitative analysis of either SCM or NIM data is the stray capacitance due to the electrostatic interaction between the sample and various parts of the AFM (tip cone, cantilever and probe holder [START_REF] Fumagalli | Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy[END_REF][START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF]). Thus the signal of interest (capacitance between the tip apex and the sample) needs to be distinguished from the stray capacitance that can be several orders of magnitude larger (typically 100-500 fF against 1 fF). It has been shown

that this stray capacitance is strongly influenced by AFM scanning conditions [START_REF] Lee | Instrumentation for direct, low frequency scanning capacitance microscopy, and analysis of position dependent stray capacitance[END_REF]. Several attempts have been made to remove this stray capacitance from raw data. For instance Lee et al [START_REF] Lee | Instrumentation for direct, low frequency scanning capacitance microscopy, and analysis of position dependent stray capacitance[END_REF] report the use of a bucking circuit to subtract an adjustable capacitance to the measured admittance. Even though this approach allows high sensitivity measurements, the exact value of the stray capacitance is unknown. Schneegans et al have worked on minimizing the stray capacitance by shielding and biasing the tip holder [START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF]. The same team proposed a dual-scan procedure to remove environmental effects [START_REF] Estevez | Specific methodology for capacitance imaging by atomic force microscopy: A breakthrough towards an elimination of parasitic effects[END_REF]. Extensive calibration processes based on analytical or numerical modelling have also been developed to obtain quantitative capacitive measurements [START_REF] Wu | Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy[END_REF][START_REF] Fumagalli | Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy[END_REF][START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF].

In parallel to the development of these AFM-based tools, the development of nanoindentation testing has been driven by the need for mechanical characterizations of small-scale systems [START_REF] Pethica | Composition and hardness profiles in ion implanted metals[END_REF][START_REF] Loubet | Vickers indentation curves of magnesium oxide (MgO)[END_REF][START_REF] Loubet | Microindentation techniques in materials science and engineering : Vickers indentation curves of elastoplastic materials[END_REF]. Capacitive transducers are widely used in nanoindentation systems [START_REF] Motoki | A nanoindentation instrument for mechanical property measurement of 3d micro/nano-structured surfaces[END_REF][START_REF] Nowakowski | Development of a precision nanoindentation platform[END_REF][START_REF] Kang | In situ thermomechanical testing methods for micro/nano-scale materials[END_REF] but they are only used as gauges to monitor the indenter column displacement. This approach has been further extended to capacitance measurements at the sample level but the measurement of tip-to-sample capacitance has essentially been used to monitor sample deformation [START_REF] Zhang | A method for determining elastic properties of micron-sized polymer particles by using flat punch test[END_REF][START_REF] Koszewski | Study of mechanical properties of rf mems switches by nanoindentation: characterization and modelling of electro-mechanical behavior[END_REF]. However the coupling of capacitive measurements to nanoindentation tests has been rarely used for the characterisation of dielectric properties of materials. To our knowledge, the only study reporting capacitance measurements on dielectrics through an indenter tip can be found in [START_REF] Koval | Relaxation processes in dielectric and electromechanical response of PZT thin films under nanoindentation[END_REF]: this study focuses on the dielectric relaxation processes induced by mechanical loading of piezoelectric thin films and the relationship with charge defect generations during loading. However, no quantitative analysis of the absolute capacitance and/or of the stray capacitance is reported.

The present paper first reports the development of a tool able to combine mechanical testing and dielectric characterisation. This set-up is essentially a nanoindentation head that has been functionalised for capacitive measurements. Secondly, a data-processing method is proposed to eliminate the effect of the stray capacitance before the quantitative analysis of the capacitive signal. Even though the effect of mechanical load is not investigated in the present study, the experimental proof-of-principle is shown and the data-processing method is validated on model dielectric thin films. On these films, dielectric permittivity is quantitatively extracted and compared to reference a macro-scale characterisation method.

Experimental details 2.1 Instrumentation

The present set-up combines different commercial instruments, with customized adapter systems.

Fig. 1 shows a Computer-Aided Design (CAD) drawing of the set-up. The nanoindentation head is a commercial actuator (InForce 50 actuator from Nanomechanics Inc), displaying a maximum load of 50mN and a static load resolution at the µN. The tip was a 5µm-large boron-doped diamond (BDD) flat-punch tip (truncated cone geometry with 30° opening angle). From an electrical point of view, this tip displays a metal-like behavior. In the present study, the tip was not used to penetrate plastically within the specimen but only to position the electrical probe on top of the dielectric surface, thus building up a MIS structure. The effect of the application of a mechanical load will be shown elsewhere. The tip is screwed on a 3 mm-long ceramic extension, which is screwed on a 1.5 cm-long tungsten extender. The ceramic part is necessary to insulate the conductive tip from the grounded extender. Electrical contacts are made with thin copper wires connected to fixed sockets.

Actuator and sample displacements are performed with linear positioners from SmarAct GmbH.

Typical travel ranges are at the cm scale with a ~1 nm resolution. The set-up presented in this paper has three translation axes: one axis translates the actuator along the indentation axis (referred as Z-axis), and two axes were dedicated to sample positioning (referred as X and Y axes). The overall stiffness of the instrument frame has been checked by indenting fused-silica specimen. Stiffness larger than 10 6 N/m has been extracted, thus validating the mechanical behavior of the overall set-up (including the different parts and workpieces along the indenting axis).

Impedance measurements were performed with an E4980A LCR-meter from Agilent with sensitivity better than 1 nS for admittance measures at 2MHz. A 'parallel model' was used for data post-processing (capacitance in parallel with a conductance). For all tests, the parallel leakage conductance was shown to be negligible compared to the capacitance of interest (i.e. the admittance phase angle was between 88 and 90°). A white LED was used to expose the MIS stack to light in order to force the semiconductor inversion regime. LED exposure avoids any heating issues which would be detrimental to nanoindentation testing.

Samples

As already stated, the present study aims at validating both the experimental set-up and the quantitative data-processing method. Thus only model materials (with well-controlled characteristics) are presented here: thin silica films deposited on silicon substrates. At this stage of the set-up validation, specimens with mm-scale homogeneity are required in order to compare the local measures (performed with this set-up) with the measures performed on a calibrated technique (Hg-probe system [START_REF] Schroder | Semiconductor Material and Device Characterization[END_REF]) that operates at the mm-scale. Substrates were n-doped silicon, with donor content of ~6.5.10 14 cm -3 (extracted by 4-point probe resistive measurements).

Substrates have been cleaned with Piranha solution (H 2 SO 4 + H 2 0 2 ) before silica growth. Silica films have been deposited in two steps:

 A first dry thermal oxidation has been performed on all specimens to grow a first 49 nm silica layer (by silicon consumption). This oxidation process has been performed for 20min at 1050°C under O 2 flow. This first oxide layer ensures an optimal Si/SiO 2 interface with low defect density.

 An extra silica layer has been further deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) over this thermal oxide. This film has been deposited at 280°C

under SiH 2 , N 2 O and Ar flows. Different thicknesses have been deposited (Table 1).

Total silica thickness has been measured by ellipsometry, while dielectric relative permittivity has been measured on a calibrated Hg-probe system.

Sample

Electrical behaviour of Metal-Insulator-Semiconductor structures

In our approach, the quantitative analysis of capacitance measurements relies on the analysis of MIS capacitive behaviour. Thus a short description of MIS diagrams and the related capacitances under applied voltage is given here (a more complete description can be found in [START_REF] Nicollian | MOS (Metal Oxide Semiconductor[END_REF]).

Let us consider a MIS structure (area ) subjected to a quasi-static electrical bias (the reference potential is taken on the metal terminal (Fig. 2)). Sweeping from negative to positive voltage forces the structure to switch from accumulation to inversion regimes, which are the two extreme possible configurations for a MIS structure.

 In the accumulation regime (Fig. 3(a)), electrons from the n-type substrate are accumulated at the insulator/semiconductor interface. As a result the MIS capacitance equals the insulator capacitance and can be described by Eq. ( 1), with and the insulator relative permittivity and thickness, respectively.

(

 In inversion regime (Fig. 3(b)), the band bending within the semiconductor is strong enough to stabilize minority carriers (holes) at the insulator/semiconductor interface.

Locally, the semiconductor has the properties of a p-type semiconductor. This inversion layer is thermodynamically stable, but might require external stimulus to be generated (light exposure in the present case). At high frequency (present case), once this inversion layer is set, the extension of the depletion region is fixed to its maximal value .

can be expressed by Eq. ( 2), with the semiconductor relative permittivity, the thermal energy (in J), the donor density and the intrinsic carrier concentration.

In this inversion regime, the MIS capacitance is due to two capacitances in series ( and ), which are both constant (Eq. ( 3)).

(

) 2
(3)

In both regimes, the capacitance which is experimentally measured is the sum of the MIS capacitance (either or ) with the stray capacitance which is unknown (Eq. ( 4)).

(

) 4
Finally the Capacitance-versus-Voltage curve (C-V) presents an S-shape as shown in Fig. 3. Both extreme levels correspond to the accumulation and inversion regimes. If the stray capacitance is independent of the applied voltage, the curve span (see figure) is only driven by the material properties (insulator thickness, permittivities of insulator and semiconductor, doping level,…). In that case, is given by Eq. ( 5).

(

) 5
Only this span will be further used in the upcoming quantitative analysis. One can notice that the stray capacitance is automatically withdrawn by working on this differential magnitude. This analytical method eliminates the stray capacitance without any fitting parameter or extensive setup calibration (to be compared to the works reported for instance in [START_REF] Wu | Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy[END_REF][START_REF] Fumagalli | Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy[END_REF][START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF]), and should be suitable for the analysis of capacitance-measures acquired on any system subjected to a stray capacitance that is voltage-independent.

Within the frame of this simple analytical model (where the 'parallel plate capacitor' model can be used) the span of C-V curve is simply obtained by subtracting Eq. ( 1) and Eq. (3), thus leading to Eq. ( 6). ( 6)

Experimental

Set-up geometry : electrode area and angular misalignment

The quantitative analysis of capacitance requires the precise knowledge of different magnitudes defining the set-up geometry: the electrode area and the angular misalignment (Fig. 4).

As already stated, the probe used in this study was a flat-punch tip, i.e. a truncated cone (Fig. 2).

As a first approximation, only the flat top part of the tip is considered. The corresponding area has been extracted from an AFM mapping of the tip. The electrode radius has been measured

to lie between 2.3 and 2.4 µm (i.e. smaller than the expected nominal 2.5 µm). For further details, refer to Supplementary material, Supp.Mat.1.

Because of unavoidable misalignments of the workpieces constituting the set-up, an intrinsic angular misalignment builds-up between the flat-punch and specimen surfaces (Fig. 4). This angle has been measured experimentally by two independent methods (see Supplementary material, Supp.Mat.2). It lies within 0.0096 and 0.012 rad. This value circa 0.01 rad is rather standard for nanoindentation systems [START_REF] Shahjahan | Effects of angular misalignment on material property characterization by nanoindentation with a cylindrical flat-tip indenter[END_REF].

Mechanical contact with the specimen for capacitive measurements

The first step of the capacitive measurement procedure is to set the flat-punch tip into contact with the specimen surface. Once the specimen surface is reached by automated approach, the nanoindenter head is set into a force-controlled mode to maintain contact with the surface. The typical pressure applied to the sample during capacitive measurements was 100kPa, thus keeping material deformation into its elastic domain (no tip penetration within the specimen, no film degradation by plastic indentation). The effect of mechanical load on material properties is not investigated in the present paper.

Capacitive measurements

For all capacitive measurements reported in the present article, the oscillating voltage level and the test frequency have been set to 2.5 V and 2MHz, respectively. Before each C-V monitoring, the MIS structure was initially set into inversion regime by applying a large positive bias and by exposing it to light for 5 s. Then measurements were performed for bias going back and forth from (inversion regime) to (accumulation regime), with a 1 V step. Between each successive capacitance measure the inversion layer was regenerated by polarising the sample at . A schematic of this "pulsed" procedure is given in Fig. 5. The pulse duration was set to 1 s. Each capacitance measure lasted for ~ 5s. and voltages were optimized for each specimen.

Stray capacitance

One of the motivations for the development of capacitive-nanoindentation was to control the stray capacitance. In typical NIM or SCM experiments, the contributions to the stray capacitance are local and they strongly depend on the probe position on the specimen [START_REF] Fumagalli | Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy[END_REF][START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF][START_REF] Lee | Instrumentation for direct, low frequency scanning capacitance microscopy, and analysis of position dependent stray capacitance[END_REF]. These contributions (i) depend on the mechanical load [START_REF] Schneegans | Capacitance measurements on small parallel plate capacitors using nanoscale impedance microscopy[END_REF][START_REF] Lee | Instrumentation for direct, low frequency scanning capacitance microscopy, and analysis of position dependent stray capacitance[END_REF] and (ii) come mostly from the tip-tosample vicinity, involving the asymmetric influence of the AFM cantilever geometry. With a nanoindenter, the probe geometry is fixed and is highly symmetrical close to the specimen (Fig. 6). The asymmetrical parts of the probe contribute to the stray capacitance at a macroscopic scale which smooths the sensitivity to surface topography or chemistry. Consequently, the stray capacitance is expected to be voltage-independent (i.e. identical in accumulation and inversion regimes) and constant over large areas, which enables its subtraction without any data loss.

Experiments

C-V curves

Typical C-V curves obtained on the 5 silica specimens are shown in Fig. 7. On these graphs, a capacitance offset has been subtracted for graphical reading convenience. This offset lies around 220-240 fF (Table 2). The dispersion on this offset has been calculated from measures performed on several spots recorded 50 µm apart from each other. This dispersion lies below 0.1 fF for most specimens, leading to a relative dispersion lower than 0.05%.

This low dispersion confirms the low sensitivity of the system to the local tip environment. The larger dispersion observed on sample (E) must be due to macroscopic set-up modifications between experiments (probably involving motions of the copper wires (Fig. 6)). The spans of C-V curves ( ) have also been extracted (Table 2). Typical dispersion on is 0.03 fF, which is the sensitivity limit of the LCR-meter (peak-to-peak noise on C-V curves). the capacitance change from accumulation to inversion regimes. It is interesting to note that sample E is close to this threshold condition, as the S-shape curve is hardly discriminated on this sample. According to Eq. 6, at first order, is proportional to (which is proportional to according to Eq. 1). Thus a relevant figure-of-merit could be the ratio (with the film permittivity and the film thickness). For sample E, this ratio is close to 4 µm -1 . Therefore, this system should apply to the characterization of any dielectric film that fulfills the condition:

. The dependence of on the oxide thickness is shown in Fig. 8. data are then compared to the simple 'parallel' model developed earlier ( from Eq. ( 6)). To do so, the specimen characteristics (permittivity and thickness, reported in Table 1) have been used as inputs into the model. As it can be seen in Fig. 8, these data are in rather good agreement for the thickest silica film, but they strongly differ as the films get thinner (numerical data can be found in Table 2). This discrepancy actually originates from the misalignment issue discussed in the "Experimental" section. The angular misalignment between the flat-punch tip and specimen surfaces induces an air wedge (Fig. 4) that affects the capacitance measurement.

Sample

With a misalignment circa 0.01 rad, the 5 µm-wide flat-tip leaves a ~50 nm air gap at its open end. Even though this air gap is negligible for the thickest films (974nm), it gets comparable to the oxide thickness on the thinnest silica films (49nm). In the following section, we propose to correct the capacitance measurement from the presence of this air wedge.

Analytical correction of the angular misalignment

In this section the analytical model is corrected from the angular misalignment .

Description of capacitance contributions

The total system capacitance is constituted of the tip-to-sample capacitance in parallel with the stray capacitance (Fig. 9(a)-(b)). The tip-to-sample capacitance is constituted of elementary capacitances (coming from the air wedge) in series with the elementary capacitances (coming from the tip-to-sample interaction) (Fig. 9(c)).

Thus each elementary capacitance is given by Eq. ( 7).

(

) 7
Figure 9: Capacitance modelling schematic.

Elementary capacitance expressions

Because the angular misalignment is small (~0.01 rad), the plate capacitor model can be applied to these elementary capacitances (the stray field at the open-end can be neglected).

Within this hypothesis, they can be expressed as follows (for coordinate references, refer to Fig. 10):

 The elementary capacitance is given by Eq. ( 8), with the sample capacitance per unit area and the elementary surface area, which will be detailed later on. At this stage, is generic and can account for the sample capacitance either in the accumulation regime ( ) or in the inversion regime ( ).

(

) 8
 The elementary capacitance is given by Eq. ( 9), with the height of the air wedge.

The surface element corresponds to the hatched sector in Fig. 10(a). can be expressed as in cylindrical coordinates (Eq. ( 10)).

for [START_REF] Zielinski | Application of different modes of nanoscale impedance microscopy in materials research[END_REF] With the flat-punch radius and the angular coordinate.

The height of the air wedge corresponds to the height of the hatched sector in Fig. 10(b).

Similarly, this magnitude can be expressed in cylindrical coordinates (Eq. ( 11)).

(

) 11
As a result, the elementary capacitance is given by Eq. ( 12).

for [START_REF] Bugg | Scanning capacitance microscopy[END_REF] Finally the corrected tip-to-sample capacitance is obtained by integrating over (Eq. ( 13)) : [START_REF] Williams | Scanning capacitance microscopy on a 25 nm scale[END_REF] where when the MIS stack is in accumulation regime, and in the inversion regime. Eq. ( 13) can then be integrated thanks to formal computational softwares

[37], thus leading to Eq. ( 14):

5.2.3 C-V curve span As previously, the C-V curve span is the difference between the capacitances in accumulation and in inversion regimes. Once more, this difference drops the contribution of the stray capacitance, thus leading to Eq. ( 15): (15) Similarly to the 'parallel' model, all the required inputs for this 'misalignment-corrected' model are obtained experimentally, without any fitting parameter. The corresponding data are then plotted in Fig. 8 (numerical data are given in Table 2), showing remarkable agreement with experimental data for all specimens.

Permittivity extraction

The previous section has shown that the 'misalignment-corrected' model can predict the span of C-V curves if the set-up user already knows the intrinsic film properties (thickness and permittivity). In terms of characterisation technique, this tool is rather expected to allow the extraction of intrinsic properties from experimental data. To do so, a home-made Python program has been developed to extract film permittivity from (a scanned value of permittivity is injected into the 'misalignment-corrected' model until the C-V spans fit). Fig. 11 reports these fitted data and compares them to permittivity values obtained on the calibrated Hg-probe system.

This figure clearly shows that permittivity is efficiently predicted. The error bars have been calculated from the dispersion on tip radius, angular misalignment and the dispersion on (Table 2). It appears that the later (due to LCR-meter sensitivity) prevails for the thickest films while dispersion on the set-up characteristics ( and ) affects essentially the thinnest films.

Conclusion

In this paper, we report the experimental development and the application of a new characterization tool made up of a nanoindentation head functionalized for capacitive measurements. First, a complete description of the system is given and a particular focus is made on the tip geometry and the angular misalignment. Then a complete data-processing method is proposed to perform quantitative analysis of the capacitance data. A fully analytical model is developed to relate the C-V curves to the system characteristics: set-up geometry and specimen properties. The proposed approach is free of adjustable parameter and should be applicable to any system with a stray capacitance that does not depend on the applied voltage. Finally, model dielectric thin films (with different thicknesses and relative permittivities) have been used to validate both the characterisation tool and the data-processing method. The extracted permittivities have been compared to a calibrated macro-scale technique and showed remarkable agreement. To our knowledge, this is the first time in literature that a quantitative analysis of the absolute capacitance is performed by using a nanoindentation head. The main strength of the whole procedure is to easily eliminate the effect of the stray capacitance which usually disturbs local capacitance measurements. Indeed, thanks to the system geometry, the stray capacitance does not depend on the applied voltage and is constant over large areas, which enables its subtraction without any data loss. Contrary to AFM-based techniques, the stray capacitance of this set-up remains unchanged when the mechanical load varies (no probe geometry change, macroscopic scale dependence), which is an advantage for the quantitative testing of loadinduced dielectric phenomena. Moreover its intermediate probe size allows this tool to fill the gap between macro-scale (Hg probe) and micro-scale (SCM, NIM) techniques for the characterization of dielectric films. Even though the effect of mechanical load is not investigated in the present study, the experimental proof-of-principle is shown and the data-processing method is validated on model dielectric thin films. This work sets the stage for the quantitative investigations of materials with load-dependent dielectric properties.

Figure 1 :

 1 Figure 1: CAD drawing of the set-up.

Figure 2 :

 2 Figure 2: Schematic of the MIS stack, with parallel plates.

Figure 3 :

 3 Figure 3: Typical C-V curve with the corresponding band diagrams in accumulation (a) and inversion (b) regimes.

Figure 4 :

 4 Figure 4: Schematic of the MIS stack with angular misalignment.

Figure 5 :

 5 Figure 5: Voltage chronogram for a full C-V measurement.

Figure 6 :

 6 Figure 6: Schematic of the set-up in close vicinity of tip-to-sample contact. The corresponding capacitive couplings are also shown. Top right: Scanning Electron Microscope view of the tip.

Fig 7

 7 Fig 7 also paves the way to defining a figure-of-merit for dielectric films to be characterized with this system. The threshold condition is essentially driven by the ability of the LCR-meter to sense

Figure 7 :

 7 Figure 7: Typical C-V profiles recorded on samples A, B, C, D and E.

Figure 8

 8 Figure 8: Evolution of , and with the oxide thickness.

Figure 10 :

 10 Figure 10: Air wedge geometrical descriptors: (a) plane view and (b) cross-section.

Figure 11 :

 11 Figure 11: Relative permittivity measured on the different samples. Both techniques (capacitive-nanoindentation and Hg-probe system) are compared.

Table 1 :

 1 Specimen description.

		Thermal silica thickness (nm)	PECVD silica thickness (nm)	Total silica thickness (nm)	Permittivity (Hg-probe)
	A	49	0	49	3.5 (+/-0.1)
	B	49	108	157	4.7 (+/-0.2)
	C	49	135	184	4.4 (+/-0.2)
	D	49	432	481	5.4 (+/-0.2)
	E	49	925	974	5.2 (+/-0.2)

Table 2 :

 2 Experimental data extracted from C-V curves (+ spans calculated from both models).

		Total
		silica			(fF)
		thickness	(fF)	(fF)	(from site		(fF)	(fF)
		(nm)			to site)
	A	49	3.49 (+/-0.04)	232.1	0.03	0.01 %	9.51	3.28
	B	157	1.72 (+/-0.03)	225.8	0.07	0.03 %	3.34	1.72
	C	184	1.52 (+/-0.03)	238.5	0.09	0.04 %	2.48	1.4
	D	481	0.55 (+/-0.03)	238.5	0.08	0.03 %	0.86	0.61
	E	974	0.20 (+/-0.03)	224.5	2.06	0.92 %	0.27	0.22

Acknowledgment

This work has been performed with the financial support of the Centre of Excellence of Multifunctional Architectured Materials "CEMAM" n° ANR-10-LABX-44-01. The CEMAM program is funded by the French Agence Nationale de la Recherche (ANR).

The authors thank the technical team of SIMaP lab (Bruno Mallery, Stéphane Massucci and Nadine Vidal) for its support, as well as members of CSI/Scientec company (Les Ulis, France) for their support for the functionalisation of the nanoindentation head: Didier Pellerin, Louis Pacheco, Alan Lecoguiec and Sylvain Poulet. Finally, the authors thank François Bertin (CEA-Leti, France) for helpful suggestions in analytical integration and Guillaume Lonchampt (student Master trainee, SIMaP) for his participation to further instrument development.