Comparative Study on Indium Precursors for Plasma-Enhanced Atomic Layer Deposition of In2O3 and Application to High-Performance Field-Effect Transistors

• Published in: ACS applied materials & interfaces 2023-11, Vol.15 (44), p.51399-51410
• Main Authors: Lee, Ho Young, Hur, Jae Seok, Cho, Iaan, Choi, Cheol Hee, Yoon, Seong Hun, Kwon, Yongwoo, Shong, Bonggeun, Jeong, Jae Kyeong
• Format: Article
• Language: English
• Subjects: Functional Inorganic Materials and Devices
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c11796

Indium oxide (In2O3) is a transparent wide-bandgap semiconductor suitable for use in the back-end-of-line-compatible channel layers of heterogeneous monolithic three-dimensional (M3D) devices. The structural, chemical, and electrical properties of In2O3 films deposited by plasma-enhanced atomic layer deposition (PEALD) were examined using two different liquid-based precursors: (3-(dimethylamino)­propyl)-dimethyl indium (DADI) and (N,N-dimethylbutylamine)­trimethylindium (DATI). DATI-derived In2O3 films had higher growth per cycle (GPC), superior crystallinity, and low defect density compared with DADI-derived In2O3 films. Density functional theory calculations revealed that the structure of DATI can exhibit less steric hindrance compared with that of DADI, explaining the superior physical and electrical properties of the DATI-derived In2O3 film. DATI-derived In2O3 field-effect transistors (FETs) exhibited unprecedented performance, showcasing a high field-effect mobility of 115.8 cm2/(V s), a threshold voltage of −0.12 V, and a low subthreshold gate swing value of