Lee Ho Young, Hur Jae Seok, Cho Iaan, Choi Cheol Hee, Yoon Seong Hun, Kwon Yongwoo, Shong Bonggeun, Jeong Jae Kyeong
Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 04763, Republic of Korea.
Department of Electronic Engineering, Hanyang University, Seoul 04763, Republic of Korea.
ACS Appl Mater Interfaces. 2023 Nov 8;15(44):51399-51410. doi: 10.1021/acsami.3c11796. Epub 2023 Oct 25.
Indium oxide (InO) 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 InO films deposited by plasma-enhanced atomic layer deposition (PEALD) were examined using two different liquid-based precursors: (3-(dimethylamino)propyl)-dimethyl indium (DADI) and (,-dimethylbutylamine)trimethylindium (DATI). DATI-derived InO films had higher growth per cycle (GPC), superior crystallinity, and low defect density compared with DADI-derived InO 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 InO film. DATI-derived InO field-effect transistors (FETs) exhibited unprecedented performance, showcasing a high field-effect mobility of 115.8 cm/(V s), a threshold voltage of -0.12 V, and a low subthreshold gate swing value of <70 mV/decade. These results were achieved by employing a 10-nm-thick HfO gate dielectric layer with an effective oxide thickness of 3.9 nm. Both DADI and DATI-derived InO FET devices exhibited remarkable stability under bias stress conditions due to a high-quality InO channel layer, good gate dielectric/channel interface matching, and a suitable passivation layer. These findings underscore the potential of ALD InO films as promising materials for upper-layer channels in the next generation of M3D devices.
氧化铟（InO）是一种透明的宽带隙半导体，适用于异质单片三维（M3D）器件的后端线路兼容沟道层。使用两种不同的基于液体的前驱体：（3-（二甲基氨基）丙基）-二甲基铟（DADI）和（，-二甲基丁胺）三甲基铟（DATI），研究了通过等离子体增强原子层沉积（PEALD）制备的InO薄膜的结构、化学和电学性质。与DADI衍生的InO薄膜相比，DATI衍生的InO薄膜具有更高的每循环生长率（GPC）、更好的结晶度和更低的缺陷密度。密度泛函理论计算表明，与DADI相比，DATI的结构空间位阻更小，这解释了DATI衍生的InO薄膜优异的物理和电学性质。DATI衍生的InO场效应晶体管（FET）表现出前所未有的性能，展示了115.8 cm²/（V·s）的高场效应迁移率、-0.12 V的阈值电压和<70 mV/十倍频程的低亚阈值栅极摆幅值。这些结果是通过采用有效氧化层厚度为3.9 nm的10 nm厚HfO栅极介电层实现的。由于高质量的InO沟道层、良好的栅极介电层/沟道界面匹配以及合适的钝化层，DADI和DATI衍生的InO FET器件在偏置应力条件下均表现出显著的稳定性。这些发现强调了ALD InO薄膜作为下一代M3D器件上层沟道有前景材料的潜力。
