• IEMN Project Sponsor: Sylvain Bollaert
  
• Coordinator: IEMN
  
• Partners: C2N, LTM
  

Abstract:

Although III-V technologies on InP substrate, using Indium (In) and Gallium (Ga) alloys, have demonstrated their superiority for high frequency and photonic applications, their development is strongly limited by the use of InP substrates that are brittle, expensive and hence hardly compatible with mass production. Moreover, these technologies should face a severe problem of restricted availability of Ga and In, either due to limited reserves (In) and/or to extraction mainly carried out in China (In, Ga). Finally, the production of Ga and In has significant detrimental consequences on the environment.

To reduce the geopolitical dependence on these materials and preserve the environment, the use of Ga and In should be limited. 2D materials (2DMs) offer a solution to reduce the required amount of active material. Thanks to their crystallographic structure, 2DMs could be grown without lattice matching requirement and hence on Silicon (Si) substrate which is the best candidate for mass applications due to its  low cost and wide availability. We then propose the development of field-effect transistors (FETs) using 2DMs on Si substrate. The selected 2DM is InSe which exhibits a direct bandgap of 1.26 eV for thickness above a few  monolayers and an electron mobility of 2000cm2/Vs, one of the best among the semiconducting 2DMs.

The achievement of this ambitious goal will rely on the expertise of 3 main technological platforms within the Renatech network: C2N, LTM and IEMN. Two growth techniques, MOCVD and MBE will be compared thanks to a deep investigation of the structural and electronic properties of the resulting epilayers. The FET technology will focus on the realization of optimized ohmic contacts and gate oxide. The electrical performance of the devices will be evaluated both at low and high frequency. The added value of the project will extend far beyond the field of FET since a wide variety of devices could benefit from the developed technology.