Team leader : Frédéric MORANCHO (Lecturer UPS).
Full-time researchers: Karine ISOIRD (Lecturer UPS), Henri TRANDUC (CNRS Researcher).
Post-doc : Hicham KOTB-MAFOZ.
PhD students : Olivier BON, Yann WEBER, Loïc THEOLIER.
The aim of these research activities is to develop new concepts (floating islands, superjunction,…) in order to overcome the limits of performances of conventional unipolar devices in the [15 V ; 1200 V] voltage range. In this way, specific on-resistances and operating frequencies of power MOSFETs have to be improved without degrading the off-state performance. Two ways are studied in order to improve these performances :
• new architectures of existing devices (for instance: FLIMOSFETs, Superjunction MOSFETs, LUDMOSFETs),
• new materials (for instance: GaN, diamond).
More precisely, the following aspects are studied:
• voltage handling capability: breakdown location and values, how to improve it using novel termination techniques,
• ON-resistance: current capability, conduction losses, how to improve it using new concepts of power devices,
• switching mechanisms: turn on and turn off, including circuit environment (command and load),
• integration: how to integrate these devices.
This work is based on the understanding of the physics of power devices. Our studies need important knowledge in the following fields :- 2D and 3D physical simulations (TCAD tools – SENTAURUS (ISE) or SILVACO)
- technological realization in the LAAS clean room
- static and dynamic characterization
A part of these activities is developed with companies, especially Freescale Semiconductors (common laboratory LISPA) and Alstom (common laboratory PEARL2).
ISE 3D simulation showing : a) doping concentrations
b) electric field distribution at breakdown, in a FLIMOSFET
invention of the team in 1999.
2D image of the FLIMOS transistor obtained by (Scanning Capacitance Microscopy).
