Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore.
NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , 119077 , Singapore.
ACS Appl Mater Interfaces. 2019 Sep 25;11(38):35438-35443. doi: 10.1021/acsami.9b10940. Epub 2019 Sep 11.
Atomic layer deposition (ALD) of ultrathin dielectric films on two-dimensional (2D) materials for electronic device applications remains one of the key challenges because of the lack of dangling bonds on the 2D material surface. In this work, a new technique to deposit uniform and high-quality AlO films with thickness down to 1.5 nm on MoS is introduced. By treating the surface using water plasma prior to the ALD process, hydroxyl groups are introduced to the MoS surface, facilitating the chemisorption of trimethylaluminum in a conventional water-based ALD system. Raman and X-ray photoelectron spectroscopy measurements show that the water plasma treatment does not induce noticeable material degradation. The deposited AlO films show excellent device-related electrical performance characteristics, including low interface trap density and outstanding gate controllability.
在二维（2D）材料上沉积用于电子器件应用的超薄介电薄膜的原子层沉积（ALD）仍然是一个关键挑战，因为 2D 材料表面缺少悬空键。在这项工作中，介绍了一种在 MoS 上沉积厚度低至 1.5nm 的均匀和高质量 AlO 薄膜的新技术。通过在 ALD 工艺之前使用水等离子体处理表面，将羟基引入 MoS 表面，促进了三甲基铝在传统的基于水的 ALD 系统中的化学吸附。拉曼和 X 射线光电子能谱测量表明，水等离子体处理不会引起明显的材料降解。沉积的 AlO 薄膜表现出优异的与器件相关的电学性能特性，包括低界面陷阱密度和出色的栅极可控性。
