Effects of Dislocation on High Temperature Transport Characteristics of Unintentionally Doped GaN  

作　　者：王茂俊 沈波 许福军 王彦 许谏 黄森 杨志坚 秦志新 张国义 

机构地区：[1]State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871

出　　处：《Chinese Physics Letters》2007年第6期1682-1685,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 60325413 and 60628402, the National Basic Research Programme of China under Grant Nos 2006CB604908 and 2006CB921607, the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China （No 705002）, the Research Fund for the Doctoral Programme of Higher Education in China （20060001018）, and the Beijing Natural Science Foundation （No 4062017）.

摘　　要：High temperature transport characteristics of unintentionally doped GaN have been investigated by means of high temperature Hall measurements from room temperature to 500^o C. The increment of electron concentration from room temperature to 500^o C is found to vary largely for different samples. The dispersion of temperature dependence of electron concentration is found to be directly proportional to the density of dislocations in GaN layers calculated by fitting the FWHM of the rocking curves in x-ray diffraction measurements （XRD）. The buildup levels in persistent photoconductivity （PPC） are also shown to be directly proportionM to the density of dislocations. The correlation of XRD, Hall and PPC results indicate that the high temperature dependence of electron density in unintentional doped GaN is directly dislocation related.High temperature transport characteristics of unintentionally doped GaN have been investigated by means of high temperature Hall measurements from room temperature to 500^o C. The increment of electron concentration from room temperature to 500^o C is found to vary largely for different samples. The dispersion of temperature dependence of electron concentration is found to be directly proportional to the density of dislocations in GaN layers calculated by fitting the FWHM of the rocking curves in x-ray diffraction measurements （XRD）. The buildup levels in persistent photoconductivity （PPC） are also shown to be directly proportionM to the density of dislocations. The correlation of XRD, Hall and PPC results indicate that the high temperature dependence of electron density in unintentional doped GaN is directly dislocation related.

关 键 词：VAPOR-PHASE EPITAXY ALGAN/GAN HEMTS FILMS HETEROSTRUCTURES VACANCIES SAPPHIRE 

分 类 号：O52[理学—高压高温物理]