Author(s): Peng, Liyuan; Liu, Shuangtao; Yang, Jing; Zhao, Degang; Liang, Feng; Chen, Ping; Liu, Zongshun

Source:MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING Volume:135 Article Number:105903 DOI:10.1016/j.mssp.2021.105903 Published:NOV 15 2021

Abstract: In this paper, it is found that the residual GaN has a great impact on the two-step-grown GaN on sapphire substrates. The samples which are grown with a conventional system baking process present a higher dislocation density than those without the baking process. It is found that, without baking, residual GaN accumulate in the MOCVD reactor, decompose, form the nucleation site on the sapphire substrate during the process of high-temperature surface treatment, and thus influence the initial nucleation process of GaN layer growth. Based on this understanding, a novel growth method to improve the quality and stability of two-stepgrown GaN on sapphire is proposed, in which the TMGa and NH3 were added in the high-temperature surface treatment process. With this method, as low as 3.71 x 107 cm-3 and 1.94 x 108 cm-3 for screw and edge dislocation density of GaN epitaxial films were achieved on sapphire.

Accession Number:WOS:000701980300005

ISSN: 1369-8001

eISSN: 1873-4081

Full Text: https://www.sciencedirect.com/science/article/pii/S1369800121002390?via%3Dihub