切割角蓝宝石基氧化镓薄膜MOCVD外延及日盲紫外光电探测器制备

摘要/Abstract

摘要： 本文使用金属有机物化学气相沉积(MOCVD)法在不同切割角的c面蓝宝石衬底上外延氧化镓(β-Ga₂O₃)单晶薄膜,揭示了衬底切割角对外延薄膜晶体质量的影响规律。研究表明,当衬底切割角为6°时,β-Ga₂O₃外延膜具有较小的X射线摇摆曲线半峰全宽(1.10°)和最小的表面粗糙度(7.7 nm)。在此基础上,采用光刻、显影、电子束蒸发及剥离工艺制备了金属-半导体-金属结构的日盲紫外光电探测器,器件的光暗电流比为6.2×10⁶,248 nm处的峰值响应度为87.12 A/W,比探测率为3.5×10¹⁵ Jones,带外抑制比为2.36×10⁴,响应时间为226.2 μs。

关键词: 超宽禁带半导体, 氧化镓薄膜, 金属有机物化学气相沉积, 日盲紫外光电探测器, 切割角, 外延

Abstract: In this work, single-crystal gallium oxide (β-Ga₂O₃) thin films were epitaxially grown on different off-cut angled c-plane sapphire substrates by metal organic chemical vapor deposition (MOCVD), and the effect of off-cut angles on the crystal quality and surface roughness of the epitaxial films were investigated. For the β-Ga₂O₃ epilayer grown on the 6° off-cut angled sapphire substrate, the full width at half maximum (FWHM) of the rocking curve is reduced to be 1.10°, together with the smallest surface roughness of 7.7 nm. Consequently, the metal-semiconductor-metal structured solar-blind ultraviolet photodetectors were fabricated by lithography, development, electron beam evaporation and lift-off techniques. The photodetector has excellent performances, including photo-dark current ratio of 6.2×10⁶, peak photoresponsivity of 87.12 A/W at 248 nm, specific detectivity of 3.5×10¹⁵ Jones, UV-visible rejection ratio of 2.36×10⁴, and total response time of 226.2 μs.

Key words: ultra-wide bandgap semiconductor, β-Ga₂O₃ film, metal organic chemical vapor deposition, solar-blind ultraviolet photodetector, off-cut angle, epitaxy

中图分类号:

汪正鹏, 张崇德, 孙新雨, 胡天澄, 崔梅, 张贻俊, 巩贺贺, 任芳芳, 顾书林, 张荣, 叶建东. 切割角蓝宝石基氧化镓薄膜MOCVD外延及日盲紫外光电探测器制备[J]. 人工晶体学报, 2023, 52(6): 1007-1015.

WANG Zhengpeng, ZHANG Chongde, SUN Xinyu, HU Tiancheng, CUI Mei, ZHANG Yijun, GONG Hehe, REN Fangfang, GU Shulin, ZHANG Rong, YE Jiandong. MOCVD Epitaxy of β-Ga₂O₃ Films on Off-Cut Angled Sapphire Substrates and Fabrication of Solar-Blind Ultraviolet Photodetector[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(6): 1007-1015.

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