PostDoc - Electrical and physical methods to investigate Reliability of GaN power HEMTs.

The IRT Saint Exupéry* accelerates science, technological research and transfer to the aeronautics and space industries for the development of reliable, robust, certifiable and sustainable innovative solutions.

At our sites in Toulouse, Bordeaux, Montpellier, Sophia Antipolis and Montreal, we offer an integrated collaborative environment composed of engineers, researchers, experts and PhD students from academia and industry for research projects and R&T services supported by technological platforms around 4 axes: advanced manufacturing technologies, greener technologies, smart technologies and methods & tools for the development of complex systems.

Our developed technologies meet the needs of industry, integrating the results of academic research.

* We are a private research foundation, supported by the French government, which funds projects in proportion to the industrial contribution and defines the regulatory framework of the foundation.

Context :

We offer a challenging post-doc in a dynamic and multidisciplinary environment. The post-doc is supported in the frame of the GANRET (Gallium Nitride Reliability for Transport) project, that aims the insertion of GaN based power electronics into severe environmental constrains applications. The project gathers several partners across different fields from space (ADS, Safran Electronics & Defense, TAS) to aeronautic with (Safran Electronics & Defense, Safran Tech and AIRBUS), including automotive with Vitesco Technology.
The industrial needs are complemented by a rich ecosystem of academic laboratories of test and technology investigation expertise and facilities. In particular the project integrates the national best-in-class scientific offer represented by four public laboratories (AMPERE à Lyon, IES à Montpellier, LAAS in Toulouse, SATIE in Paris) and a private academic laboratory (ICAM in Toulouse).

Description :

Gallium Nitride (GaN) power devices present higher electron mobility, lower capacitance values and lower on-state resistance than their silicon counterparts, leading to overall performances improvement particularly in higher frequencies and higher efficiency. This technology aims to enable the transition toward power electronics conversion. However, the characterization and fine understanding of the reliability of these components remains one of the last obstacles.

The aim of the post-doc, is to strengthen the knowledge and know-how in characterization methods, understanding of the reliability of new GaN HEMT power switches.

The post-doc will be dedicated to establish and define stable and repeatable test protocols that take into account trapping mechanisms, for measuring the fundamental electrical parameters used as indicators of the GaN power devices health. Indeed, parameters such as for example the threshold voltage and the channel resistance are strongly dependent from the trapping state of the device, making the measurements unstable and not suitable for health tracking. Therefore, the objective of the work is to put the device in a reproducible state, allowing meaningful comparison of its health state before and after aging characterizations. The established methodology will be demonstrated on reliability tests such as “High Temperature Gate Bias” and “High Temperature Reversed Bias”...

PosDoc tasks :

• A deep understanding of the trapping behaviour and its influence on GaN power device electrical characteristics
• Establishment of repeatable and reliable test protocols to characterize GaN components coming from different suppliers

• Thesis in a relevant area of applied physics, or electrical engineering
• A solid background in semiconductor physics
• Ability to work with experts from a broad range of scientific and technology backgrounds

Applicants may also advantageously have experience in one or more of the following areas:

• A first experience in power devices characterization
• Fluent spoken and written English
• Semiconductor reliability

Involved partners :
IRT Saint-Exupery is one of the eight Institutes of Technology in France aiming to enhance R&D synergy between academia and industry. It fosters innovation by gathering partners around common roadblocks and builds projects on private-public funding basis to tackle them. This is a unique environment where industrial practical needs are directly matched to the scientific body of knowledge available in academia and research laboratories. The IRT Saint Exupery in Toulouse, in particular target this strategic industrial competitive edge in the following key areas: Reliability, green technologies,power electronics.
LAAS (Laboratory of Analysis and Architecture of Systems) is a CNRS research unit located in Toulouse. Research, innovation and transfer are tied. The lab has a history of strong relationships with industry and works in a large number of collaborative projects with international, national and regional industries of all size. Within LAAS, the ISGE team has a long experience in design and reliability of Si and wide-bandgap (WBG) power devices. These activities rely on the its recently created Platform of Reliability tOOls for Failure analysis (PROOF) dedicated to wide bandgap devices for both RF and power applications.