Previous work

The “New devices” team of the ISGE group has experience of more than ten years in design, manufacturing, characterization and modelling of power devices and integrated systems. Its activities were mainly focused on devices and systems using silicon as the basic semiconductor material, which is used in a wide majority of power applications because of its low cost and its mature technology. Thus, in order to improve the performances of these power devices (increase in reverse voltage capability, frequency and temperature operations, reduction of conduction and switching losses) and, in particular, to overcome the limits of performance of the conventional unipolar power devices, the team invented new power devices architectures in silicon technology. One can quote, for example:

  • Invention of the U-diode concept (use of a dielectric in the bulk to handle a part of the reverse voltage) and manufacture of the trench LDMOSFET (or LUDMOS) for Smart Power integrated circuits, mainly for automotive applications (45 V devices). This technology was transferred to the integrated circuits SmartMOS™ and HiperMOS™ of Freescale Semiconductors.
  • Invention of the “Floating Islands” (FI) concept and manufacture of FLIMOS and FLYMOS™ with one level of FI between drain and source (80 V FLIMOS transistor) and with two levels of of FI (200 V FLYMOS™ transistor).
  • Design of high voltage (1200 V) power Superjunction MOSFETs with deep trenches using an original junction termination (the DT2 for “Deep Trench Termination”), filled with BenzoCycloButene (BCB).

This works were based on the physical phenomena understanding specific to power devices. These studies required competences in these fields:

  • 2D and 3D physical simulations with TCAD tools like SENTAURUS-SYNOPSIS or SILVACO,
  • technological realization,
  • static and dynamic characterizations of the devices.

A large part of these works was carried out within the framework of collaborations with companies, in particular within the framework of laboratories common PEARL2 (with ALSTOM), the LCIP1, the LCIP2 and the LISPA (with in the past Motorola, from now on Freescale Semiconducteurs).