Impact of in situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance
Journal article, 2022

The impact on the performance of GaN high electron mobility transistors (HEMTs) of in situ ammonia (NH3) pre-treatment prior to the deposition of silicon nitride (SiN) passivation with low-pressure chemical vapor deposition (LPCVD ) is investigated. Three different NH3 pre-treatment durations (0, 3, and 10 min) were compared in terms of interface properties and device performance. A reduction of oxygen (O) at the interface between SiN and epi-structure is detected by scanning transmission electron microscopy (STEM )-electron energy loss spectroscopy (EELS) measurements in the sample subjected to 10 min of pre-treatment. The samples subjected to NH3 pre-treatment show a reduced surface-related current dispersion of 9% (compared to 16% for the untreated sample), which is attributed to the reduction of O at the SiN/epi interface. Furthermore, NH3 pre-treatment for 10 min significantly improves the current dispersion uniformity from 14.5% to 1.9%. The reduced trapping effects result in a high output power of 3.4 W mm(-1) at 3 GHz (compared to 2.6 W mm(-1) for the untreated sample). These results demonstrate that the in situ NH3 pre-treatment before LPCVD of SiN passivation is critical and can effectively improves the large-signal microwave performance of GaN HEMTs.

LPCVD

traps

GaN HEMTs

microwave

NH3 pretreatment

Author

Chen Ding Yuan

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Axel R. Persson

Linköping University

Kai-Hsin Wen

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Daniel Sommer

United Monolithic Semiconductors (UMS)

Jan Grunenputt

United Monolithic Semiconductors (UMS)

Herve Blanck

United Monolithic Semiconductors (UMS)

Mattias Thorsell

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Olof Kordina

SweGaN AB

Vanya Darakchieva

Linköping University

Lund University

Per O. A. Persson

Linköping University

Jr-Tai Chen

SweGaN AB

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Semiconductor Science and Technology

0268-1242 (ISSN) 1361-6641 (eISSN)

Vol. 37 3 035011

Subject Categories

Medical Equipment Engineering

Materials Chemistry

Condensed Matter Physics

DOI

10.1088/1361-6641/ac4b17

More information

Latest update

2/3/2022 1