晶格匹配氮化镓和氧化锌基外延薄膜衬底材料ScAlMgO_4晶体生长研究

Study on the Growth of Lattice-matched ScAlMgO_4 Substrates for GaN and ZnO-based Film Epitaxy

采用提拉法成功生长了氮化镓和氧化锌基外延薄膜晶格匹配的ScA lMgO4单晶衬底材料,晶体呈透明白色,尺寸为30mm×59mm,表面部分沿解理面有裂纹。粉末X射线衍射(XRD)分析表明经1400℃固相反应烧结的原料基本合成了ScA lMgO4多晶相。初步的偏光显微镜观察、晶体的粉末XRD表征、透过光谱和双晶摇摆测试表明晶体具有较好的光学性质和结晶质量。研究表明晶体本身的层状结构、较大的温度梯度和热应力的不均匀性是生长过程中引起晶体开裂的几个主要原因。

A transparent white ScAlMgO4 crystal used as lattice-matched substrate for GaN and ZnO epitaxial film has been grown by Czochralski method . The as-grown crystal boules were about Ф30mm×59mm in dimension and cracked slightly along cleavage plane . With the XRD pattern of sintered raw analysis , it is confirmed that solid-state reaction sintering at 1400℃ ScAlMgO4 polycrystal phase preliminarily synthesized. Polarizing microscopy , XRD pattern , transmission spectrum and X-ray rocking curve characterization indicate the as-grown crystal is of fine crystalline and optical property . Studies show that the cracking phenomena of the ScAlMgO4 crystals occurred during the growth process are mainly originated from its intrinsic layer structure , relatively larger temperature gradient and inhomogeneity of thermal stress.