Advanced Atomic Layer Deposition Technologies for Micro-LEDs and VCSELs

Yen-Wei Yeh, Su-Hui Lin, Tsung-Chi Hsu, Shouqiang Lai, Po-Tsung Lee, Shui-Yang Lien, Dong-Sing Wuu, Guisen Li, Zhong Chen, Tingzhu Wu and Hao-Chung Kuo
Nanoscale Res Lett 16, 164 (2021) —Published in November 2021


In recent years, the process requirements of nano-devices have led to the gradual reduction in the scale of semiconductor devices, and the consequent non-negligible sidewall defects caused by etching. Since plasma-enhanced chemical vapor deposition can no longer provide sufficient step coverage, the characteristics of atomic layer deposition ALD technology are used to solve this problem. ALD utilizes self-limiting interactions between the precursor gas and the substrate surface. When the reactive gas forms a single layer of chemical adsorbed on the substrate surface, no reaction occurs between them and the growth thickness can be controlled. At the Å level, it can provide good step coverage. In this study, recent research on the ALD passivation on micro-light-emitting diodes and vertical cavity surface emitting lasers was reviewed and compared. Several passivation methods were demonstrated to lead to enhanced light efficiency, reduced leakage, and improved reliability.