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 035011Subject Categories
Medical Equipment Engineering
Materials Chemistry
Condensed Matter Physics
DOI
10.1088/1361-6641/ac4b17