摘要
用ＮＨ３作氮源的ＧＳＭＢＥ方法在晶向为（０００１）的α－Ａｌ２Ｏ３衬底上生长了非有意掺杂的单晶ＧａＮ外延膜，ＧａＮ膜呈Ｎ型导电，室温时的最高迁移率约为１２０ｃｍ２／（Ｖ·ｓ），相应的非有意掺杂电子浓度为９．１×１０１７ｃｍ－３．对一些ＧａＮ膜进行了变温Ｈａｌ测试，通过电阻率、背景电子浓度以及Ｈａｌ迁移率随温度的变化研究了ＧａＮ外延膜的导电机理．结果表明，当温度较低时，以电子在施主中心之间的输运导电为主；当温度较高时，以导带中的自由电子导电为主．
Abstract Single crystalline unintentionally doped GaN films are grown on (0001) α Al 2O 3 substrates by GSMBE method using ammonia as nitrogen source. The highest mobility of these films was about 120 cm 2/(V·s) with a corresponding autodoping electron concentration of about 9.1×10 17 cm -3 . The electron transport properties of these films are investigated by analyzing the results of variable Hall measurements. The Hall results show that the dominant electron transport occurs in the autodoping centers when temperature is low and that conduction through free electrons in the conduction band becomes dominant when temperature becomes higher.
基金
国家"九五"重点科技攻关计划
博士后科学基金
