Sn-doped β-Ga 2 O 3 thin films grown on off-axis sapphire substrates by LPCVD using Ga-Sn alloy solid source

• Published in: Physica scripta 2024-06, Vol.99 (6), p.65417
• Main Authors: Yang, Han, Wu, Songhao, Ma, Chicheng, Liu, Zichun, Liu, Liwei, Zhang, Yiyun, Ma, Yuan Xiao, Yi, Xiaoyan, Wang, Junxi, Wang, Yeliang
• Format: Article
• Language: English
• ISSN: 0031-8949; 1402-4896
• DOI: 10.1088/1402-4896/ad4e12

Adopting low pressure chemical vapor deposition (LPCVD), Sn-doped β -Ga 2 O 3 thin films were heteroepitaxially grown on c-plane sapphire substrates with off-axis angles towards 〈11–20〉 direction. The influences of off-axis angle on crystal structures, electrical properties, surface morphology, and chemical compositions were thoroughly investigated. As a result, the crystallinity of the β -Ga 2 O 3 films is improved with increasing off-axis angles because in-plane rotational domains are effectively suppressed, demonstrating a full width at half maximum (FWHM) down to 0.64°. Correspondingly, the Hall carrier mobility is promoted from 4.7 to 17.9 cm 2 /V·s at carrier concentration of 9 × 10 17 cm −3 , which is believed highly competitive among reported Sn-doped β -Ga 2 O 3 films by LPCVD. These results demonstrate an alternative pathway to heteroepitaxially grow high electrical quality n-doped β -Ga 2 O 3 films for the advancement of Ga 2 O 3 materials and devices.