The effect of HCl on the α-Ga2O3 thin films fabricated by third generation mist chemical vapor deposition

Tatsuya Yasuoka,Giang T Dang,Tamako Ozaki,Miyabi Fukue,Kanta Asako,Li Liu,Toshiyuki Kawaharamura,Yuna Ishikawa

doi:10.1063/5.0051050

Abstract

α-Ga2O3 thin films were grown on a c-plane sapphire substrate by a third generation mist chemical vapor deposition system. The surface roughness was measured by atomic force microscopy, and the composition of Ga2O3 was measured by x-ray photoelectron spectroscopy. It was found that HCl affects the growth rate, purity, and surface roughness of α-Ga2O3 films. The growth rate increased with the HCl supply. The thickness, surface roughness, and chemical state analyses indicate that three growth modes occurred depending on the Ga supply rate and HCl/Ga supply ratio and the purity was improved by optimizing the HCl/Ga supply ratio and Ga supply rate.

Highlights

To improve these characteristics, a high growth temperature is necessary to increase the atomic migration
Α-Ga2O3 thin films were grown on c-plane sapphire substrates, the size of which is 15 × 15 mm[2] by a third generation mist CVD system, which consist of several solution chambers, a mixing chamber, and a fine channel (FC) reactor
The second generation mist CVD system consists of a solution chamber and a fine channel reactor

Summary

Introduction

To improve these characteristics, a high growth temperature is necessary to increase the atomic migration. The mixture solution of HCl and de-ionized water was used as the supply source of HCl, whose concentration was 570 mmol/l, and the HCl/Ga ratio in the mixing chamber was controlled by the c.g. flow rates of different solution chambers.

Results

Conclusion