Suppression of Dispersive Effects in AlGaN/GaN High-Electron-Mobility Transistors Using Bilayer SiNx Grown by Low Pressure Chemical Vapor Deposition
Journal article, 2015

A bilayer SiNx passivation scheme has been developed using low pressure chemical vapor deposition (LPCVD), which effectively suppresses the dispersive effects in AlGaN/GaN high-electron-mobility transistors (HEMTs) for microwave power operation. The bilayer LPCVD passivation is compared with in-situ SiNx passivations by metal-organic chemical vapor deposition (MOCVD) and ex-situ SiNx passivations by plasma-enhanced chemical vapor deposition (PECVD). The HEMTs were fabricated and characterized in terms of pulsed IV, transient drain current, and load pull. The devices passivated with in-situ MOCVD SiNx or PECVD SiNx exhibit significant current slump (similar to 40%) and knee-voltage walkout, while the bilayer LPCVD SiNx passivated device shows negligible current slump (similar to 6%) and knee-voltage walkout. These characteristics are directly reflected in the large signal operation, where HEMTs with bilayer LPCVD SiNx have the lowest dynamic ON-state resistance and highest output power (5.4 W/mm at 3 GHz).

trapping

AlGaN/GaN high-electron-mobility transistors

passivation

current collapse

Author

Tongde Huang

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Anna Malmros

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Johan Bergsten

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Sebastian Gustafsson

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Olle Axelsson

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Mattias Thorsell

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Electron Device Letters

0741-3106 (ISSN)

Vol. 36 6 537-539

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/led.2015.2427294

More information

Created

10/7/2017