Normally-Off Operation GaN Based MOSFETs for Power Electronics

GaN is promising for high-power, high-temperature devices due to some of its large bandgap, high critical electric field, and high saturation velocity compared with Si and SiC. The MOSFET structure can be operated at a positive threshold voltage in the normally-off mode, which is preferable for powe...

Full description

Saved in:
Bibliographic Details
Main Authors: Niiyama, Y., Ootomo, S., Kambayashi, H., Ikeda, N., Nomura, T., Kato, S.
Format: Conference Proceeding
Language:English
Subjects:
Annealing
Electric resistance
Gallium nitride
Interface states
MOSFETs
Photonic band gap
Power electronics
Power transistors
Silicon carbide
Threshold voltage
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:GaN is promising for high-power, high-temperature devices due to some of its large bandgap, high critical electric field, and high saturation velocity compared with Si and SiC. The MOSFET structure can be operated at a positive threshold voltage in the normally-off mode, which is preferable for power transistors in terms of fail-safe operation. In order to realize MOSFET operation, low resistance in the n + -contact layer and good interface quality at SiO 2 /GaN are strongly required. We could reduce the interface state density at SiO 2 /GaN by annealing at 900degC for 30 min. Furthermore, we successfully realized the formation of the n+ contact layer by annealing at 1260degC for 30 s. Finally, we have fabricated GaN MOSFETs and have achieved more than 2.5 A operation in the normally-off mode at more than 250degC. The breakdown voltage was more than 1550 V.
ISSN:1550-8781
2374-8443
DOI:10.1109/csics.2009.5315770