PhD thesis (M/F) Design of gallium nitride (GaN) power devices and functions for high voltage applications

2 May 2024
Job Information

Organisation/Company

CNRS

Department

Laboratoire d'analyse et d'architecture des systèmes

Research Field

Engineering
Physics
Technology

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

22 May 2024 - 23:59 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

35

Offer Starting Date

1 Jul 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

To respond to the climate emergency, society has initiated a major change in terms of resource management and energy consumption, in particular by adopting alternative energy sources in transport and in buildings, thus imposing major changes in the power electronics industry. This requires new generations of power devices and conversion architectures that should lead to optimizing energy management by reducing their size (mass, volume) and being as close as possible to the actuators (motor, turbine).
Wide bandgap semiconductors, in particular gallium nitride (GaN) with its exceptional electronic properties, must make it possible to produce these active devices operating in a harsh environment (high voltage, high temperature, high frequency, radiation). It is therefore essential to develop the technological sector specific to the realization of these power devices and functions.

Energy management is one of the greatest challenges our society will face in the 21st century. It is on this challenge that the research activities of the proposed subject are positioned; the design of new power switches is essential: it is necessary to minimize losses, to ensure better management of electrical energy, to increase performance (breakdown voltage, current rating, efficiency) and robustness by improving the intrinsic characteristics of semiconductor devices. Wide bandgap semiconductor materials such as gallium nitride (GaN) are suitable candidates to address this challenge.
To date, GaN devices are overwhelmingly lateral devices with AlGaN/GaN heterostructures. Although manufactured on large silicon substrates and therefore low cost, these devices exhibit many limitations: low threshold voltages VTH, limited breakdown voltage BV (< 1 kV) and in trade-off with power density, high dynamic on-resistances, etc. This is the reason why it is essential to manufacture vertical devices that can withstand high voltages (> 1 kV) while maintaining a small surface.
It is within this framework that the VERTIGO project, funded by the “electronic” PEPR (Priority Research Programs and Equipment) of the “France 2030” investment plan, fits.
In this project, the task of the doctoral student recruited here will be twofold:
The first phase of this thesis work aims at the design by LAAS of vertical 1200 V power transistors in connection with the CRHEA and CEA Leti laboratories, in order to define the optimal stacking of the different GaN epitaxial layers and to propose device architectures compatible with the technological means of these two laboratories which will be in charge of the technological realization of the said devices. As the project aims to manufacture purely vertical devices, bipolar structures can also be evaluated by simulation in addition to unipolar structures (FET, MOS).
In a second step, elementary functions ("senseFET", anode voltage sensor, use of the vertical parasitic bipolar, isolation and integration of functions for close control, etc.) will then be developed to go towards a monolithic integration of power functions that allow to make the most of the performance of the material. In collaboration with the LAPLACE laboratory, taking close control into account will allow better optimization of the “device-control” system, in particular on the specification of the threshold voltage and the choice of design compromises.

Requirements

Research Field

Engineering

Education Level

PhD or equivalent

Research Field

Physics

Education Level

PhD or equivalent

Research Field

Technology

Education Level

PhD or equivalent

Languages

FRENCH

Level

Basic

Research Field

Engineering

Years of Research Experience

None

Research Field

Physics

Years of Research Experience

None

Research Field

Technology

Years of Research Experience

None

Additional Information
Additional comments

This thesis will be carried out within the framework of the VERTIGO project financed by the “electronic” PEPR (Priority Research Programs and Equipment) of the “France 2030” investment plan.

Website for additional job details

https://emploi.cnrs.fr/Offres/Doctorant/UPR8001-FREMOR-017/Default.aspx

Work Location(s)

Number of offers available

1

Company/Institute

Laboratoire d'analyse et d'architecture des systèmes

Country

France

City

TOULOUSE

Geofield

Where to apply

Website

https://emploi.cnrs.fr/Candidat/Offre/UPR8001-FREMOR-017/Candidater.aspx

Contact

City

TOULOUSE

Website

http://www.laas.fr

STATUS: EXPIRED