Atomic layer etching-enabled interface engineering for reduced subthreshold swing and improved uniformity in p-channel GaN MOSFETs

Z Zixian Jiang (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,) Z Zhiyuan Liu T Tingang Liu (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,) H Haicheng Cao (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,) S Saravanan Yuvaraja (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,) G Glen Isaac Maciel García (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,) C Chuanju Wang (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,) P Patsy Arely Miranda-Cortez (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,) L Leo Raj Solay (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,) K Kexin Ren G Georgian Melinte (Core Laboratories) C Camelia Florica M Mritunjay Kumar X Xiaohang Li (Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,)

Abstract

In this work, enhancement-mode p-MOSFETs on p-GaN/AlGaN/GaN-on-Si substrates were fabricated using a gate recess process that combines reactive ion etching (RIE) with atomic layer etching (ALE), where ALE is employed as an interface engineering approach following conventional plasma etching to mitigate recess-induced interface damage. Compared with RIE-only devices, the RIE + ALE devices yield smoother surfaces and significantly suppress interface trap density. These interface improvements lead to enhanced subthreshold characteristics and markedly tighter device-to-device uniformity. In particular, the subthreshold swing decreased from 365 ± 179 to 149 ± 17 mV/dec, while the off-state leakage current was suppressed from 1.9 ± 3.6 × 10−7 to 8.5 ± 5.5 × 10−9 mA/mm. These results demonstrate that ALE provides an effective interface engineering approach for suppressing interface damage and enabling uniform enhancement-mode p-MOSFETs, highlighting its potential for reliable GaN complementary metal–oxide–semiconductor logic and power integrated circuits.

Article Details

Volume / Issue Vol. 128, Issue 15
Published April 13, 2026
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (14)

Z

Zixian Jiang

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,

Z

Zhiyuan Liu

T

Tingang Liu

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,

H

Haicheng Cao

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,

S

Saravanan Yuvaraja

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,

G

Glen Isaac Maciel García

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,

C

Chuanju Wang

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,

P

Patsy Arely Miranda-Cortez

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,

L

Leo Raj Solay

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900,

K

Kexin Ren

G

Georgian Melinte

Core Laboratories

C

Camelia Florica

M

Mritunjay Kumar

X

Xiaohang Li

Advanced Semiconductor Laboratory, Electrical and Computer Engineering Program, CEMSE Division, King Abdullah University of Science and Technology (KAUST) 1 , Thuwal 23955-6900,