Effects of V/Ⅲ ratio on structural, optical, and electrical properties of semi-polar high Al-content Si-doped n-AlGaN epi-layers. (15th November 2022)

• Record Type: Journal Article
• Authors: Shen, Yang; Zhang, Xiong; Fan, Aijie; Chen, Bin; Tian, Yong; Luo, Xuguang; Lyu, Jiadong; Lai, Mu-Jen; Hu, Guohua; Cui, Yiping
• Is Part Of: Materials science in semiconductor processing. Volume 151(2022)
• Publication Date: 2022-11-15
• Subjects: Semi-polar AlGaN -- Ⅴ/Ⅲ ratio -- Cation vacancy and its complex -- Surface morphology -- Optical and electrical properties; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2022.107002
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Effects of Ⅴ/Ⅲ ratio on structural, optical, and electrical properties of semi-polar (11 2 ‾ 2) n-Al0.61 Ga0.39 N epi-layers grown by metal organic chemical vapor deposition technology were extensively investigated. Insufficient supply of effective nitrogen atoms on the epitaxial surface under low Ⅴ/Ⅲ ratio was responsible for the decrease in growth rate. The grain density on the epitaxial surface decreased significantly with increasing Ⅴ/Ⅲ ratio and hence led to a reduction in surface roughness. The three emission peaks observed in the photoluminescence spectra were verified to be related to substantial carbon atoms on nitrogen sites (CN ), isolated cation vacancies (VⅢ ), and their complexes (VⅢ complex), respectively. Electrical properties of semi-polar n-Al0.61 Ga0.39 N was improved with increasing Ⅴ/Ⅲ ratio since an N-rich environment was identified to be effective in suppressing the incorporation of CN -related defects. However, the formation of VⅢ and VⅢ complex was enhanced under over-rich nitrogen ambient, resulting in a degradation in electrical properties. Raman analysis showed that the in-plane stress of n-Al0.61 Ga0.39 N was hardly affected by variation in V/III ratio.