两种新型衬底材料LiAlO_2和LiGaO_2晶体的腐蚀形貌和缺陷研究  

ETCHING MORPHOLOGY AND DEFECTS OF TWO NOVEL SUBSTRATESLiAlO2 AND LiGaO2 CRYSTALS

作　　者：徐科[1,2,3] 邓佩珍[1,2,3] 徐军[1,2,3] 周永宗 刘文军[1,2,3] 蒋树声 蒋建华[1,2,3] 

机构地区：[1]中国科学院上海光学精密机械研究所 [2]南京大学固体微结构物理实验室 [3]中国科学院北京高能物理研究所

出　　处：《硅酸盐学报》1998年第3期281-285,共5页Journal of The Chinese Ceramic Society

基　　金：国家"863"新材料领域资助

摘　　要：ＬｉＡｌＯ２和ＬｉＧａＯ２是目前找到的和ＧａＮ晶格失配率最小的两种晶体，其失配率分别为１．４％和０．２％．本研究分别利用温梯法和提拉法成功地生长出了ＬｉＡｌＯ２和ＬｉＧａＯ２单晶．通过化学侵蚀、光学显微镜、透射电子显微镜和Ｘ射线衍射貌相术对两种晶体中的缺陷特征进行了分析，研究了晶体特性、生长方法和缺陷形成的关系．用温梯法生长的ＬｉＡｌＯ２晶体质量良好，晶体中无气泡、包裹物．ＬｉＡｌＯ２晶体中的位错密度约为３．８×１０４—６．０×１０４／ｃｍ２，晶体中的主要缺陷为亚晶界或镶嵌，可能是由于温度场不稳定及生长速率太快造成的．而用普通的提拉法生长的ＬｉＧａＯ２晶体由于原料按非化学计量比挥发，致使组分偏离，容易产生γ－Ｇａ２Ｏ３包裹物，包裹物和位错的形成具有一定的相互促进作用，往往形成平行于（００１）面的亚晶界，通过调整原料配比及生长工艺参数可克服上述问题．测得ＬｉＧａＯ２晶体的位错密度为７．０×１０５—９．２×１０５／ｃｍ２．LiAlO2 and LiGaO2 are promising substrates newly found for the epitaxy of GaN. In the present work,the crystalline qualities of LiAlO2 grown by temperature gradient technique(TGT) and LiGaO2 grown by Cz method were examined by using chemical etching ,optical microscope, TEM,synchrotron source X-ray topography respectively.The results show that LiAlO2 crystals are free from bubbles and inclusions,and the dislocation density measured on (100) crystal plane is about 3.8×104—6.0×104cm-2. The main defect is the subgrain boundaries, which may be caused by the fluctuation of temperature field in the furnace or too rapid growth rate. These two parameters are required to be optimized further. γ-Ga2O3 inclusions tend to emerge in LiGaO2 crystals owing to the volatilization of Li2O,therefore,a lot of dislocations are induced, forming the subgrain boundaries parallel to (001) plane. High_quality LiGaO2 crystal can be obtained by using the starting materials with excess Li2O and adopting appropriate growth parameters. TGT is more suitable in growing crystals whose constituents may vaporize unstoichiometrically than Cz method. 

关 键 词：铝酸锂 镓酸锂 缺陷 衬底材料 晶体 腐蚀 

分 类 号：TN304.204[电子电信—物理电子学]