Electronic and Electrical Engineering: Fully Funded Swansea University PhD Scholarship: Gate-oxide reliability of wide bandgap power MOSFETs: offline prediction of lifetime and online monitoring of degradation

Funding providers: Swansea University

Subject areas: Electronic and Electrical Engineering

Project start date: 

• 1 July 2024 (Enrolment open from mid-June)
• 1 October 2024 (Enrolment open from mid-September) 

Supervisors:

• Dr Mohammad Monfared (mohammad.monfared@swansea.ac.uk)
• Professor Mike Jennings

Aligned programme of study: PhD in Electronic and Electrical Engineering

Mode of study: Full-time 

Project description: 

The wide bandgap (WBG) power MOSFET is more prone to early failure than its Si counterparts despite its recent success. One of the most significant contributing factors to the overall reliability of these devices is degradation or even complete failure of the gate oxide. Specifically, gate threshold voltages shift from their original value with prolonged application, mainly due to gate oxide thickness reduction and high electric fields.

Reliability refers to a product's performance remaining within specifications for a specific period of time. According to the semiconductor industry, after 10 years of operation under nominal conditions, at most 100 devices per million can fail from oxide breakdown.

The goal of this project is to a) study and examine the failure mechanisms of WBG (particularly gallium nitride) devices, b) compare different methodologies for predicting or modelling the gate-oxide reliability of WBG power MOSFETs and identify the gap for both offline reliability and lifetime estimation and possible online condition monitoring from transistor signals, c) design, simulate and practically implement the required circuit configuration and the final multi-channel test rig for concurrent reliability testing and examining the failure mechanisms, d) develop conventional statistical approaches and artificial intelligence (AI) models from data provided by testing a large number of samples under controlled conditions to validate and generalise the research findings and e) recommend future work to implement the realised improvements.

This PhD project aims to create a meaningful impact through the collaboration between EPRG (Engineering and Power Research Group) at Swansea University and Vishay Intertechnology.