IEICE Trans - Deep-Donor-Induced Suppression of Current Collapse in an AlGaN-GaN Heterojunction Structure Grown on Si

Deep-Donor-Induced Suppression of Current Collapse in an AlGaN-GaN Heterojunction Structure Grown on Si

Taketoshi TANAKA
Norikazu ITO
Shinya TAKADO
Masaaki KUZUHARA
Ken NAKAHARA

Publication
IEICE TRANSACTIONS on Electronics Vol.E103-C No.4 pp.186-190
Publication Date: 2020/04/01
Publicized: 2019/10/11
Online ISSN: 1745-1353
DOI: 10.1587/transele.2019ECP5011
Type of Manuscript: PAPER
Category: Semiconductor Materials and Devices
Keyword:
AlGaN/GaN HFETs, deep donor, deep acceptor, GaN, semi-insulating,

Full Text: FreePDF

Summary:
TCAD simulation was performed to investigate the material properties of an AlGaN/GaN structure in Deep Acceptor (DA)-rich and Deep Donor (DD)-rich GaN cases. DD-rich semi-insulating GaN generated a positively charged area thereof to prevent the electron concentration in 2DEG from decreasing, while a DA-rich counterpart caused electron depletion, which was the origin of the current collapse in AlGaN/GaN HFETs. These simulation results were well verified experimentally using three nitride samples including buffer-GaN layers with carbon concentration ([C]) of 5×10¹⁷, 5×10¹⁸, and 4×10¹⁹ cm^-3. DD-rich behaviors were observed for the sample with [C]=4×10¹⁹ cm^-3, and DD energy level E_DD=0.6 eV was estimated by the Arrhenius plot of temperature-dependent I_DS. This E_DD value coincided with the previously estimated E_DD. The backgate experiments revealed that these DD-rich semi-insulating GaN suppressed both current collapse and buffer leakage, thus providing characteristics desirable for practical usage.