超晶格插入层对Si基上GaN薄膜位错密度的影响(英文)  

Influence of the Thickness of Super Lattice Interlayer on the Dislocation Density of HT-GaN on Si(111)

作　　者：刘晓峰[1] 冯玉春[1] 彭冬生[2] 

机构地区：[1]深圳大学光电子学研究所,深圳518060 [2]中国科学院,西安光机所,西安710068

出　　处：《电子器件》2008年第1期61-64,共4页Chinese Journal of Electron Devices

基　　金：深圳大学开放实验室基金资助(200515);广东省科技基金资助(2B2003A102)

摘　　要：为了降低MOCVD外延生长Si基GaN的缺陷密度,尝试引入超晶格插入层。界面突变的超晶格插入层能有效地阻挡由缓冲层延伸出来的位错。即使超晶格本身也产生位错,但位错的产生率比阻挡率低,所以超晶格总体起阻挡作用,可以减少后续生长的HT-GaN(高温氮化镓)的位错密度。研究了超晶格厚度对HT-GaN的位错密度的影响,比较了超晶格厚度不同的3个样品,并采用高分辨双晶X射线衍射(DCXRD)对GaN进行结晶质量的分析,分别用H3PO4+H2SO4混合溶液和熔融KOH对样品进行腐蚀并用扫描电子显微镜(SEM)对腐蚀的样品进行观察。用H3PO4+H2SO4腐蚀过的样品比用KOH腐蚀过的样品的位错密度大,进一步验证了之前有报道过的H3PO4+H2SO4溶液同时腐蚀螺位错和混合位错而KOH只腐蚀螺位错。分析结果表明,引入适当厚度的超晶格插入层,可以有效地降低后续生长的GaN的位错密度。To decrease the dislocation density of HT-GaN on Si（111） with metalorganic chemical vapor deposition （MOCVD）, super lattice interlayer is introduced. The super lattice with mutative interface can effectively prevent the dislocation originating from the buffer layer from penetrating to the surface of GaN film. The influence of the thickness of super lattice interlayer on the dislocation density of HT-GaN on Si（111） is investigated. Three sampies with different thickness of super lattice layer are studied. The high-resolution double crystal X-ray diffraction （DCXRD） is used to analyze the crystal quality. Furthermore, the three samples are etched by H3PO4 ＋H2SO4 mixed resolution and melted KOH respectively and then observed by scanning electron microscopy （SEM）. The later experiment shown that the dislocation density of anyone of the three samples etched by Hs PO4 ＋ H2SO4 mixed resolution apparently higher than that etched by melted KOH, which further justify the reported conclusion that Hs PO4 ＋ H2SO4 mixed resolution etch screw dislocation and mixture dislocation while melted KOH etch screw dislocation. Both experiments shows that modest thickness of super lattice interlayer effectively decline the dislocation density of HT-GaN on Si（111）.

关 键 词：GAN SI(111) 超晶格 位错密度 

分 类 号：TN304.054[电子电信—物理电子学]