无位错Te-GaSb(100)单晶抛光衬底的晶格完整性

采用液封直拉(LEC)法批量生长的直径2英寸(1英寸=2.54 cm)n型Te-GaSb(100)单晶的位错腐蚀坑密度(EPD)通常低于300 cm^-2,达到无位错水平。本文利用X射线摇摆曲线以及倒易空间图(RSM)对这种GaSb单晶抛光衬底的晶格完整性和亚表面损伤情况进行了分析表征,结果表明经过工艺条件优化的化学机械抛光处理,GaSb单晶衬底表面达到原子级光滑,不存在亚表面损伤层。利用分子束外延在这种衬底上可稳定生长出高质量的Ⅱ类超晶格外延材料并呈现出优异的红外探测性能。在此基础上,对CaSb衬底材料的物性、生长制备和衬底加工条件之间的内在关系进行了综合分析。

Lattice Perfection of Dislocation-Free (100) Te-GaSb Single Crystal Polished Substrate

The dislocation etch pit density (EPD) of the 2-inch diameter n-type (100) Te-GaSb single crystal grown in batches by the liquid encapsulated Czochralski (LEC) method is usually lower than 300 cm^-2, reaching dislocation-free level. In this paper, the lattice perfection and subsurface damage of this GaSb single crystal polished substrate were characterized by X-ray rocking curve and reciprocal space map (RSM). The results show that after chemical mechanical polishing with optimized process conditions, the surface of GaSb single crystal substrate is atomically smooth, and there is no subsurface damaged layer. High-quality type-Ⅱ superlattice epitaxial materials can be stably grown on this substrate by molecular beam epitaxy and exhibit excellent infrared detection performance. On this basis, the internal relationship between the physical properties, growth preparation and substrate processing conditions of GaSb substrate materials was comprehensively analyzed.