基于mist CVD的高纯相α-Ga_(2)O_(3)生长与光电响应特性研究  

Mist CVD Grown High-Phase-Purity α-Ga_(2)O_(3)and Its Photoresponse Performance

作　　者：姚苏昊 张茂林 季学强 杨莉莉 李山 郭宇锋[2] 唐为华 YAO Suhao;ZHANG Maolin;JI Xueqiang;YANG Lili;LI Shan;GUO Yufeng;TANG Weihua(Innovation Center for Gallium Oxide Semiconductor(IC-GAO),College of Integrated Circuit Science and Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;National and Local Joint Engineering Laboratory for RF Integration and Micro-Packing Technologies,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学,集成电路科学与工程学院氧化镓半导体创新中心,南京210023 [2]南京邮电大学,射频集成与微组装技术国家地方联合工程实验室,南京210023

出　　处：《人工晶体学报》2025年第2期233-243,共11页Journal of Synthetic Crystals

基　　金：国家重点研发计划(2022YFB3605404);国家自然科学基金联合项目(U23A20349);江苏省双创人才团队项目(JSSCTD202351)。

摘　　要：超宽禁带半导体氧化镓(Ga_(2)O_(3))在功率电子和信息传感方面有重要应用,其高效、经济的制备方法是实现产业推广的重要环节。本文报道了一种Sn辅助雾相化学气相沉积(mist CVD)技术,基于这种非真空、低成本方法在c面蓝宝石衬底上成功外延生长了高质量纯相α-Ga_(2)O_(3)薄膜。实验通过mist CVD生长温度的调控探索,获得了纯相α-Ga_(2)O_(3)薄膜外延生长的温度区间为500~600℃。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱、X射线光电子能谱(XPS)等方法对纯相α-Ga_(2)O_(3)薄膜进行了物相、形貌、光学特征、元素含量和价态表征,结果表明600℃生长的α-Ga_(2)O_(3)薄膜具有更高的结晶度,更致密和平整的表面形貌。进一步地,通过构建金属-半导体-金属(MSM)结构的光电探测器,研究了α-Ga_(2)O_(3)薄膜的深紫外(DUV)光电响应性能。500和600℃制备α-Ga_(2)O_(3)薄膜,其光暗电流比(PDCR)分别为5.85×10^(5)和7.48×10^(3),外量子效率(EQE)分别为21.8%和520%,响应度分别为0.044和1.09 A/W。在6 V偏压和254 nm光照下,500℃生长的α-Ga_(2)O_(3)薄膜的响应时间为0.97/0.36 s,600℃的样品响应时间却增大为2.89/4.92 s,这主要是Sn辅助生长在α-Ga_(2)O_(3)薄膜内形成了施主杂质,影响了载流子的输运效率。Ultra-wide bandgap semiconductor gallium oxide(Ga_(2)O_(3))has important applications in power electronics and information sensing,its efficient and economical preparation is important to realize its industrial promotion.In this paper,a Sn-assisted mist chemical vapor deposition(mist CVD)technique is reported,based on which high-quality pure-phase α-Ga_(2)O_(3)thin films were successfully epitaxially grown on c-plane sapphire substrates by this non-vacuum,low-cost method.The mist CVD growth temperature regulation experiment shows that the temperature for epitaxial growth of pure-phaseα-Ga_(2)O_(3)thin films is between 500 and 600℃.The physical phase,morphology,optical features,elemental content and valence of the pure-phase α-Ga_(2)O_(3)thin films were characterized by using X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-visible spectrophotometer,and X-ray photoelectron spectrometer(XPS)techniques.The results indicate that the α-Ga_(2)O_(3)thin films grown at the temperature of 600℃ possess a higher degree of crystallinity,a denser and flatter surface morphology.Further,the deep-UV(DUV)photoresponse properties of α-Ga_(2)O_(3)thin films were investigated by constructing photodetectors with metal-semiconductor-metal(MSM)structures.Forα-Ga_(2)O_(3)thin films prepared at 500 and 600℃,the photodetectors show photo-to-dark current ratios(PDCR)of 5.85×10^(5) and 7.48×10^(3),external quantum efficiencies(EQE)of 21.8% and 520%,and responsivities of 0.044 and 1.09 A/W,respectively.Under 6 V bias voltage and 254 nm illumination,the response time is 0.97/0.36 s for α-Ga_(2)O_(3)thin film grown at 500℃,while it increases to 2.89/4.92 s for the sample grown at 600℃,which may be ascribed to the formation of donor impurities within theα-Ga_(2)O_(3)thin films by Sn-assisted growth,and affecting the carrier transport efficiency.

关 键 词：α-Ga_(2)O_(3) 雾相化学气相沉积 Sn辅助生长 光电响应 沉积温度 掺杂激活 

分 类 号：O78[理学—晶体学] TN304.21[电子电信—物理电子学]