低温GaN形核层的形核速率对GaN外延薄膜晶体质量的影响  

Effect of Nucleation Rate of Low Temperature GaN Nucleation Layer on the Crystal Quality of GaN Epitaxial Thin Films

作　　者：廖建华[1,2] 尚林[1,2] 贾伟[1,2] 余春燕[1,2] 李天保[1,2] 许并社[1,2] 

机构地区：[1]太原理工大学新材料界面科学与工程教育部和山西省重点实验室,太原030024 [2]太原理工大学新材料工程技术研究中心,太原030024

出　　处：《人工晶体学报》2016年第4期880-885,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(61475110;61404089;21471111);山西省自然科学基金(2014021019-1;2014011016-6);山西省科技创新重点团队(2012041011)

摘　　要：采用金属有机化学气相沉积方法系统研究了在蓝宝石衬底上低温GaN形核层的形核速率对GaN外延薄膜晶体质量的影响机理。利用高分辨X射线衍射仪、原子力显微镜、光致发光光谱和Hall测试仪表征材料的位错密度、表面形貌以及光、电学性能。研究结果表明随着形核速率的增加,GaN形核层更倾向于三维生长模式;当形核速率达到1.92/s时退火后生成尺寸为100 nm宽、32 nm高的均匀形核岛,随后生长的未掺杂GaN外延薄膜层的螺型和刃型位错密度以及黄带峰强度达到最小值,并且其具有最高的载流子迁移率和最低的载流子浓度。Effect of nu-cleation rate on the crystal quality of GaN epitaxial thin films on sapphire substrates were analyzed by the metal organic chemical vapor deposition method. Dislocation density,surface morphology,optical and electrical properties of materials were characterized by high resolution X ray diffraction, atomic force microscopy, photoluminescence spectra, and Hall testing instruments respectively. As the nucleation rate increasing,the GaN nucleation layer is more inclined to three dimensional growth mode. When the nucleation rate of the GaN shaped islands reached to 1. 92 A/ s after annealing,they have uniform shaped islands with the size of 100 nm wide and 32 nm high. At this time,screw and edge dislocation density and yellow peak intensity of this material reached to minimum value,and this material has the highest mobility and minimum carrier concentration.

关 键 词：形核速率 形核层 GAN 金属有机化学气相沉积 

分 类 号：O484[理学—固体物理]