Author(s): Chu, JY (Chu, Jiayan); Wang, Q (Wang, Quan); Feng, C (Feng, Chun); Jiang, LJ (Jiang, Lijuan); Li, W (Li, Wei); Liu, HX (Liu, Hongxin); Wang, Q (Wang, Qian); Xiao, HL (Xiao, Hongling); Wang, XL (Wang, Xiaoliang)

Source: JAPANESE JOURNAL OF APPLIED PHYSICS Volume: 60 Issue: 3 Article Number: 035506 DOI: 10.35848/1347-4065/abe341 Published: MAR 1 2021

Abstract: In this study, AlGaN/GaN high-electron-mobility transistors (HEMTs) were grown on a GaN template and GaN substrate under the same growth conditions. It was observed that, in the HEMT structure grown on the GaN substrate, mobility decreased because of an increase in the two-dimensional electron-gas (2DEG) density; the origin of these redundant electrons was studied. The 2DEG density decreased with decreasing temperature, this phenomenon closely related to unintentionally induced shallow donors with ionization energy calculated to be around 67.8 meV. After ratio regulation, the 2DEG density returned to a normal level; this combined with photoluminescence, confirmed for the first time that the abnormal increase of 2DEG density in HEMT structure grown on the GaN substrate is associated with nitrogen vacancies. Therefore, increasing the ratio is beneficial for obtaining higher mobility by returning the 2DEG density to a normal level.

Accession Number: WOS:000620995500001

ISSN: 0021-4922

eISSN: 1347-4065

Full Text: https://iopscience.iop.org/article/10.35848/1347-4065/abe341