From design to electrical characterization

The aim is to obtain power components with voltage, temperature and switching frequency ranges never achieved. This will require a technological breakthrough by changing materials from silicon to large-gap semiconductors, as well as the design of new structures (3D approach, modification of surface design, etc.).

This requires the development of specific technological building blocks in the Si, GaN and diamond sectors. In order to characterise the components produced, it is necessary to adapt the existing measurement benches and to develop new ones dedicated to these new large-gap components (PROOF platform at LAAS).

• New concepts of normally-off AlGaN/GaN HEMT

For many years, the ISGE team has been a coordinator and partner in national projects on the GaN power chain, both for the development of lateral and vertical AlGaN/GaN HEMTs (ANR VERTIGAN, CPiGaN, PEPR Electronique VERTIGO, etc.).

As part of the IPCEI Nano2022 project, we have designed and are developing at the LAAS RENATECH platform a new normally-off HEMT concept with a nanostructured P-GaN gate, enabling threshold voltages in excess of 2 V to be achieved. This technology, based on epitaxial P-GaN wells along the gate and developed in collaboration with the CRHEA, is a first step towards the monolithic integration of more complex power functions on GaN.

• Diamond power devices

Because of its properties, diamond is an interesting candidate for power electronics that naturally work at higher junction temperatures, in a smaller volume and with improved energy efficiency.

We are designing and developing the technological building blocks for the production of diamond power components such as TMBS diodes, PIN diodes and U-MOSFET transistors through various projects (ANR's MOVeToDiam, LAPIN113) bringing together french specialists in diamond epitaxy (GEMaC, LSPM) and power electronics (AMPERE).

Contact: Karine ISOIRD, Frédéric MORANCHO, Patrick AUSTIN, Josiane TASSELLI

• Silicon Carbide (SiC) devices

Research on monolithic integration of power conversion functions on SiC is being carried out in partnership with the LAPLACE, AMPERE and L2n laboratories, and using the CNM laboratory's VDMOS-SiC technology chain. They focus on the design and production of new SiC power chip architectures that combine VDMOS and JBS diodes to create high-performance switching cells, with maximum integration and minimum interconnection. The resulting converters use only a minimum number of chips, which optimises PCB layout, cost and large-scale productivity, since fewer transfer stages are required. ANR PRC MUS²-IC project

Contact: Abdelhakim BOURENNANE

Robustness and reliability

To increase the robustness of these components, it is essential to take into account, from the design step, constraints such as EMC, ESD, strong electric fields, radiations and temperature .

Power management systems play a crucial role in electronic circuits, controlling the power supply for critical applications such as automotive brake assist and battery charge regulation. Our research aims to make these components more robust with increasing complexity and ever smaller dimensions. We are deepening our understanding of the physics behind the operation of components subjected to various stresses, in order to gain a better understanding of their reliability and propose solutions aimed at optimising their immunity or implementing effective protection.

Contact: David TRÉMOUILLES