Master thesis project: Radiation effect of GaN based HEMTs for RF and power electronic applications

Background
In Europe, wide bandgap semiconductor technology has been an active research area with great effort from academic, military and industrial stakeholders. GaN as one of wide band gap semiconductors is playing an increasingly important role in various emerging markets, such as 5G/6G, vehicle and smart grid for energy-saving, as well as in all high-voltage industrial scenarios. RISE has been involved in several national and international research and development projects regarding GaN based RF and power electronic devices for different applications. A team at Nano Technology Unit at RISE is aiming to provide solutions utilizing their expertise on GaN technology to make contributions to related societal challenges in digitalisation, energy efficiency and mobility of the future.

Purpose of the project
Whenever silicon-based semiconductors devices reach their limits, GaN based devices are promising candidates enabling higher switching frequencies together with higher energy conversion efficiencies. As known, GaN HEMT has advantages on bandwidth, power efficiency and compact size, which are well suited to the military and space electronic demands for ship-, aircraft- and satellite related applications. In such operation environments, the devices will commonly be subject to fluxes of radiations, such as high energy protons/electrons if used in low earth orbit as well as neutrons or gamma rays if used in nuclear or military electronic systems.

This thesis project is a part of a couple of ongoing projects at RISE, which focus on GaN based High Electron Mobility Transistor (HEMT) for power electronic and RF applications. For instance, one ongoing project on radiation effect of GaN HEMTS that financed by the U.S. Office of Naval Research Global (ONR Global), https://www.ri.se/en/what-we-do/projects/radiation-effects-on-gan-hemts. The master-degree student will be involved mainly in characterizations of various GaN based HEMTs on different substrates, such as on Si and SiC. In particular, the radiation effects on the HEMTs with different device configurations will be compared and studied before and after the radiations. The key device performance parameters will be investigated including threshold voltage, output current rate, off-state leakage, gate leakage, breakdown electrical field, thermal stability and bandwidths. The outcome will be utilized to optimize the HEMT device’s design and fabrication for operating them at harsh environment under radiations in high or low-temperature conditions.

Project activities will include

• Literature survey on the state-of-the-art in the frame of the project objectives.
• Characterization and performance comparison of various fabricated HEMTs at RISE before and after designed radiation tests.
• Result analysis for better understanding of the defects and their influence on the device’s performance.
• Final report (Master’s thesis).

Who are you?
We are looking for the master student in nanotechnology and microelectronics or equivalent, who can perform the degree project during the Autum 2024. Relevant courses as well as lab experience are considered merits.

About RISE
RISE is Sweden’s research institute and innovation partner. Through our international collaboration programmes with industry, academia and the public sector, we ensure the competitiveness of the Swedish business community on an international level and contribute to a sustainable society. RISE is an independent, state-owned research institute, which offers unique expertise and over 130 testbeds and demonstration environments for future-proof technologies, products and services.

Terms
The project will be performed at Nano-Technology Unit at RISE’s premises in Kista over a 6-month period, corresponding to 30 ETCS. For such an approved work, a stipendium of 30 000 SEK will be awarded. The starting time of this project in September 2024 can be discussed.

Welcome with your application!
If you have any questions, pleace contact Qin Wang, Senior Expert, +46 707727838. The application deadline is August 25 2024. The selection process will begin at the end of August.