缓冲层温度对Si(11上GaN表面形貌影响  

Effect of Buffer Temperature on Epilayer Morphology for GaN on Si(111)

作　　者：朱军山[1] 赵丽伟[1] 孙世龙[1] 滕晓云[1] 刘彩池[1] 徐岳生[1] 

机构地区：[1]河北工业大学材料学院,天津300130

出　　处：《液晶与显示》2006年第1期6-10,共5页Chinese Journal of Liquid Crystals and Displays

基　　金：教育部新世纪优秀人才支持计划;河北省自然科学基金资助项目(No.E2005000042)

摘　　要：用不同温度的Al N缓冲层在Si(111)衬底上外延GaN薄膜。通过对薄膜表面扫描电子显微镜(SEM)和高分辨率双晶X射线衍射(DCXRD)的分析,研究了缓冲层生长温度对外延层表面形貌的影响,分析解释了表面形貌中凹坑的形成及缓冲层生长温度对凹坑的影响。结果表明:缓冲层生长温度通过影响缓冲层初始成核密度和成核尺寸来影响外延层表面形貌。较低温度下的Al N缓冲层,在衬底表面形成的成核颗粒因温度太低,无法运动到相邻的颗粒而结合成大的成核颗粒,因此成核密度高,成核尺寸小;高温生长的Al N缓冲层,成核颗粒有足够的能量运动到相邻的成核颗粒,因此使成核颗粒的尺寸增大,成核密度低。这种初始成核密度和尺寸的不同,造成外延层形貌的差异,如表面形貌中凹坑的密度和大小就是受初始成核的直接影响。通过实验和分析,提出了外延生长的物理模型。GaN epitaxial layers were grown on Si（111） substrates with AIN buffer layers at different growth temperature. X ray diffraction（DCXRD） and scanning electron microscope（SEM） were used as analysis tool to reveal the relation between growth temperature of buffer layer and epilayer surface morphology. The ＂pits＂ on epitaxial surface and the relation with buffer growth temperature were explained through these analysis. It indicates that the buffer growth temperature influences surface morphology through nucleation seed density and dimension dropped on the Si（111） substrate at initial time of buffer growth. When the buffer temperature was low, nucleation seeds were frozen on the surface of substrate and could not move to neighboring seeds. Nucleation seeds density was high and dimension was small. When the buffer temperature was high, the nucleation seeds had enough energy to merge with other seeds and density of seeds was low and dimension was big. This nucleation difference caused the epilayer morphology difference. Through this analysis, one growth model was created to guide the later experiments.

关 键 词：GAN SI(111) 缓冲层 表面形貌 

分 类 号：O472[理学—半导体物理] O484.4[理学—物理]