Self-terminating contactless photo-electrochemical (CL-PEC) etching for fabricating highly uniform recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs)

Toguchi Masachika; Miwa Kazuki; Horikiri Fumimasa; Fukuhara Noboru; Narita Yoshinobu; Ichikawa Osamu; Isono Ryota; Tanaka Takeshi; Sato Taketomo

Title	en Self-terminating contactless photo-electrochemical (CL-PEC) etching for fabricating highly uniform recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs)
Creator	en Toguchi, Masachika en Miwa, Kazuki en Horikiri, Fumimasa en Fukuhara, Noboru en Narita, Yoshinobu en Ichikawa, Osamu en Isono, Ryota en Tanaka, Takeshi en Sato, Taketomo NRID 1000050343009
Accessrights	metadata only access
Rights	en Copyright 2021 Authors. This article is distributed under a Creative Commons Attribution (CC BY) License.
Subject	NDC 540
Description	Abstract en Contactless photo-electrochemical (CL-PEC) etching was used to fabricate recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs). Self-termination of etching was observed during CL-PEC etching on an AlGaN barrier layer whose residual thickness had a uniform value of 6 nm overall on the same chip. After tetramethylammonium hydroxide post-treatment, the root-mean-square roughness of the etched surface was around 0.4 nm, which had smoothness comparable to that of the unetched surface. Recessed-Schottky HEMTs showed a positive shift in V-th, the suppression of drain leakage currents, and an improvement in the subthreshold-slope value as compared with planar-gate HEMTs. By applying a metal-insulator-semiconductor (MIS)-gate structure, the gate and drain leakage currents were significantly reduced, leading to an increased input dynamic range. Furthermore, the standard deviations (sigma) of the V-th of CL-PEC-etched recessed-Schottky HEMTs and recessed-MIS HEMTs were very small, 5.5 and 16.7 mV, respectively. These results showed that the CL-PEC etching process is promising for the fabrication of recessed-gate AlGaN/GaN HEMTs having excellent uniformity for normally-off device operations.
Publisher	en American Institute of Physics (AIP)
Date	Issued2021-07-08
Language	eng
Resource Type	journal article
Version Type	NA
Identifier	HDL http://hdl.handle.net/2115/82407
Relation	isIdenticalTo DOI https://doi.org/10.1063/5.0051045
Journal	PISSN 0021-8979 EISSN 1089-7550 NCID AA00693547 en Journal of Applied Physics Volume Number130 Issue Number2 Page Start24501
Oaidate	2023-07-26