Missions

Electrothermal modeling of GaN devices for application to the design of high switching frequency power converters
This project is part of a collaboration between the IEMN's "Power Microwave Components and Devices" team and the L2EP's "Power Electronics" team, both of which have complementary skills. The aim is to develop a complete chain of skills, from the characterization and electrothermal modeling of GaN power devices (GaN diodes and GaN-HEMT transistors) to the design and production of a high-frequency converter. GaN technology is particularly well suited to the development of power electronics converters with high switching frequencies (> 1MHz).
The studies will be carried out in collaboration with ST MICROELECTRONICS, which will fabricate the components. The work will involve developing methods to characterize packaged and unpackaged components based on static DC and dynamic RF broadband measurements, using S-parameters determination obtained with a vector network analyzer (VNA). This requires the development of characterization cells and specific circuits to access 50Ω. What's more, since these measurements have to be performed at high voltage, biases with sufficient bandwidth and high power handling must be used.
From characterization, the work will consist in determining the equivalent scheme of components based on extrinsic and intrinsic elements, as well as carrying out thermal measurements. The impact of casing type will also be studied. The aim is to determine electro-thermal models of components applicable over a wide frequency band, for the design of converters operating at frequencies above 1MHz. To this end, circuit-type software (ADS or SPICE) will be used.
In addition, the effects of gate lag and drain lag on transistors will be investigated using pulsed high-voltage measurements, and the effects of current collapse on diodes and transistors during switching will be analyzed and modeled. Dynamic resistance models will then be developed to determine conduction losses.
The models developed will be used in simulation to design and optimize HF converters for specific applications.

Activités

Experimental activities in the IEMN characterization center

Compétences

Knowledge of GaN components
Knowledge of component characterization methods
Knowledge of S-parameters
Use of ADS software
Ability to develop electrothermal models

Contexte de travail

Experimental laboratory work
Measurements in characterization room

The position is located in an area covered by the protection of scientific and technical potential (PPST), and therefore requires, in accordance with regulations, that your arrival be authorized by the competent MESR authority.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

No risk

Informations complémentaires

NA