基于GaN同质衬底的高迁移率AlGaN/GaNHEMT材料  

Highmobility AlGaN/GaN high electronic mobility transistors on GaN homo-substrates

作　　者：张志荣[1] 房玉龙[1] 尹甲运[1] 郭艳敏 王波 王元刚 李佳[1] 芦伟立[1] 高楠 刘沛[2] 冯志红[1] Zhang Zhi-Rong1） Fang Yu-Long1） Yin Jia-Yun1） Guo Yan-Min1） Wang Bo1） Wang Yuan-Gang1） Li Jia1） Lu Wei-Li1） Gao Nan1） Liu Pei2） Feng Zhi-Hong1） 1）(National Key Laboratory of ASIC, Hebei Semiconductor Research Institute, Shiiiazhuang 050051, China） 2） （China Academy of Aerospace Standardization and Product Assurance, Beijing 100071, China)

机构地区：[1]专用集成电路国家级重点实验室,河北半导体研究所,石家庄050051 [2]中国航天标准化与产品保证研究所,北京100071

出　　处：《物理学报》2018年第7期211-218,共8页Acta Physica Sinica

基　　金：国家重点研究发展计划(批准号：2017YFB0404100)资助的课题.

摘　　要：研究了表面预处理对GaN同质外延的影响,获得了高电子迁移率AlGaN/GaN异质结材料.通过NH_3/H_2混合气体与H_2交替通入反应室的方法对GaN模板和GaN半绝缘衬底进行高温预处理.研究结果表明,NH_3/H_2能够抑制GaN的分解,避免粗糙表面,但不利于去除表面的杂质,黄光带峰相对强度较高;H_2促进GaN分解,随时间延长GaN分解加剧,导致模板表面粗糙不平,AlGaN/GaN HEMT材料二维电子气迁移率降低.采用NH_3/H_2混合气体与H_2交替气氛模式处理模板或衬底表面,能够清洁表面,去除表面杂质,获得平滑的生长表面和外延材料表面,有利于提高AlGaN/GaN HEMT材料电学性能.在GaN衬底上外延AlGaN/GaN HEMT材料,2DEG迁移率达到2113 cm^2/V·s,电学性能良好.Gallium nitride （GaN） has great potential applications in high-power and high-frequency electrical devices due to its superior physical properties. High dislocation density of GaN grown on a foreign substrate leads to poor crystal quality and device reliability. The homo-epitaxial growth of GaN material has low dislocation density, which is the foundation of high performance of A1GaN/GaN higheleetronic mobility transistor. However, it is difficult to prepare flat surface of GaN template or GaN substrate in thermal treatment process under the metal-organic chemical vapor deposition （MOCVD） ambient condition in which hydrogen （H2） is commonly used to clean the substrate surface, i.e., to remove impurities from the substrate surface, since H2 would greatly enhance GaN decomposition in MOCVD high-temperature condition and etch GaN into roughness surface In this work, an alternation gas model of ammonia/hydrogen （NHa/H2） mixed gas and H2 gas is designed. This technique is used in a thermal treatment process of GaN template and substrate by MOCVD. Then, we in-situ grow A1GaN/GaN HEMTs （high electron mobility transistors） on GaN template and GaN substrate, respectively. A series of alternation gas samples with various H2 treatment times is investigated. Optical microscope and atomic force micro- scope are used to observe the morphologies of GaN template and A1GaN/GaN HEMTs and two-dimensional electron gas （2DEG） mobility and density of A1GaN/GaN HEMTs are measured by contactless Hall measurement. Optical properties of A1GaN/GaN HEMTs are analyzed by photoluminescence at room temperature. The residual impurities of C and O in the GaN epilayer and the interracial region between GaN epilayer and GaN substrate are analyzed by secondary ion mass spectrometry. The study results show that H2 enhances GaN decomposition in MOCVD at high temperature, and GaN decompo- sition greatly strengthens with H2 treatment time increasing leading to rough surface and the decrease of 2DEG mobility. The NHa/H2 mixed g

关 键 词：金属有机物化学气相沉积 氮化镓 热处理 同质外延 

分 类 号：TN386[电子电信—物理电子学]