In situ Etching of β-Ga2O3 using tert-Butyl Chloride in an MOCVD System

作     者：Gorsak, Cameron A. Bowman, Henry J. Gann, Katie R. Smith, Kathleen T. Steele, Jacob Jena, Debdeep Schlom, Darrell G. Xing, Huili Grace Thompson, Michael O. Nair, Hari P. 

作者机构：Department of Materials Science and Engineering Cornell University IthacaNY14853 United States PARADIM REU Cornell University IthacaNY14853 United States School of Applied and Engineering Physics Cornell University IthacaNY14853 United States School of Electrical and Computer Engineering Cornell University IthacaNY14853 United States Kavli Institute Cornell for Nanoscale Science Cornell University IthacaNY14853 United States Leibniz-Institut für Kristallzüchtung Max-Born-Str. 2 Berlin12489 Germany 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Activation energy 

摘      要：In this study, we investigate in situ etching of β-Ga2O3 in a metal-organic chemical vapor deposition (MOCVD) system using tert-Butyl chloride (TBCl). We report the successful etching of both heteroepitaxial (2̅01)-oriented and homoepitaxial (010)-oriented β-Ga2O3 films over a wide range of substrate temperature, TBCl molar flows, and reactor pressures. We identify that the likely etchant is HCl (g) formed by the pyrolysis of TBCl in the hydrodynamic boundary layer above the substrate. The temperature dependence of the etch rate reveals two distinct regimes characterized by markedly different apparent activation energies. The extracted apparent activation energies suggest that at temperatures below ~800 °C the etch rate is likely limited by desorption of etch products, while at higher substrate temperatures chemisorption of HCl limits the etch rate. The relative etch rates of heteroepitaxial (2̅01) and homoepitaxial (010) β-Ga2O3 were observed to scale by the ratio of the surface energies indicating an anisotropic etch. For (010) homoepitaxial films, relatively smooth post-etch surface morphology was achieved by tuning the etching parameters. © 2024, CC BY.