Highly Scaled p-GaN-gate HEMTs for Low Voltage Power Electronics

Rising global energy demands, driven by the advent of artificial intelligence (AI), cloud computing, and Internet of Things (IoT) devices, underscore the need for more efficient power electronics. In particular, power switches based on wide bandgap semiconductors such as gallium nitride (GaN) have emerged as promising alternatives to traditional silicon devices for low-voltage (10-100 V) applications. This work investigates the design, fabrication, and scaling of p-GaN-gate highelectron-mobility transistors (HEMTs). A p-GaN-gate epitaxial structure was developed with considerations for short channel effects. A self-aligned, gate-first process employing tungsten metallization was implemented to enable gate lengths as small as 100 nm. Device scaling was studied systematically, revealing the importance of gate aspect ratio and gate-to-drain spacing in managing short channel effects and maintaining breakdown voltage. Electrical characterization showed strong device performance, although contact resistance accounted for a substantial portion of total on-resistance. To address this, a modified fabrication approach incorporating regrown contacts was introduced, resulting in reduced contact resistance and improved overall device characteristics. The combined results highlight practical strategies for enhancing the performance and scalability of p-GaN-gate HEMTs for next-generation low-voltage power electronics.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2025

Author dc:creator

• Darmawi-Iskandar, Patrick

Advisor dc:contributor.advisor

• Palacios, Tomás

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright retained by author(s)

Licence dc:rights.uri

• https://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/163698

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/163698