GaN薄膜中的马赛克结构随厚度发生的变化  

Mosaic structure in epitaxial GaN film varying with thickness

作　　者：张韵[1] 谢自力[1] 王健[1] 陶涛[1] 张荣[1] 刘斌[1] 陈鹏[1] 韩平[1] 施毅[1] 郑有炓[1] 

机构地区：[1]南京大学电子科学与工程学院江苏省光电信息功能材料重点实验室,南京210093

出　　处：《物理学报》2013年第5期279-283,共5页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2011CB301900;2012CB619304);国家高技术研究发展计划(批准号:2011AA03A103);国家自然科学基金(批准号:60990311;60820106003;60906025;60936004;61176063);江苏省自然科学基金(批准号:BK2008019;BK2011010;BK2010385;BK2009255;BK2010178)~~

摘　　要：利用高分辨率X射线衍射(HRXRD)对MOCVD系统中生长在c面Al2O3上的不同厚度的GaN薄膜内马赛克结构进行了研究.在对称面的三轴X射线衍射曲线中,用两种方法计算得到晶粒的垂直关联长度和水平关联长度,两者均随着薄膜厚度的增加而增加,并且垂直关联长度近似膜厚从倒易空间图中得出的横向关联长度也有相同的趋势,结合非对称面的衍射曲线用Williamson-Hall方法和外推法分别拟合出晶粒的面外倾斜角和面内扭转角,他们随着薄膜厚度的增加显著减少,这一切都表明厚度的增加,晶粒的单向有序排列越来越整齐,外延片的质量越来越高.In this article. We report on the study of mosaic structures of different thick GaN films grown on sapphire （0001） by metalorganic chemical vapor deposition （MOCVD）, using high resolution x-ray diffraction. The result from the symmetrical reflections show that the mosaic vertical and lateral correlation lengths that are calculated by two methods increase with film thickness increasing, and the vertical correlation lengths are close to the film thickness, and the same trend in the lateral correlation lengths derived from the reciprocal space maps. By the help of asymmetrical reflections and Williamson-Hall extrapolation method, the tilt and twist mosaic drop with thickness increasing at different rates. All this shows that the increase in thickness lads to the more uniform and neat grain arrangement and the higher-quality epitaxial wafers.

关 键 词：GaN薄膜马赛克结构 厚度 HRXRD 

分 类 号：O484.1[理学—固体物理]