热处理GaSb衬底对近距离升华法制备CdZnTe外延膜的影响

摘要/Abstract

摘要： 衬底的表面质量对生长膜层的质量有重要影响,衬底表面的粗糙度、均匀性、附着物残留及氧化层均是其表面质量的评价标准。本文报道了一种热处理方法,通过近距离升华设备原位去除GaSb(001)衬底上的氧化层后用于制备CdZnTe外延膜。通过控制热处理的温度和时间,获得洁净且平整的较优衬底状态。利用原子力显微镜和X射线光电子能谱表征了热处理对GaSb衬底形貌和成分的影响,采用双晶X射线摇摆曲线对经过热处理后的GaSb衬底上生长的CdZnTe外延膜的结晶质量进行了评价。为了深入研究这种异质界面附近微观缺陷的性质和外延形成机制,还对CdZnTe/GaSb截面进行了TEM分析研究。GaSb衬底在600 ℃经过180 s热处理后,可以去除衬底表面大部分氧化物且相对平整,提高了CdZnTe外延膜的结晶质量,在双晶X射线摇摆曲线中的半峰全宽为94″,接近已报道的块体CdZnTe晶体的结晶质量。

关键词: CdZnTe, GaSb, 外延生长, 薄膜, 物理气相沉积, 热处理, 半导体

Abstract: The surface quality of the substrate has an important effect on the quality of the growth film. The roughness, uniformity, adhesion residue and oxide layer of the substrate are the evaluation criteria of its surface performance. In this paper, an in-situ thermal treatment method to remove the natural oxides on GaSb (001) substrates for epitaxial growth of CdZnTe films by close-spaced sublimation method was reported. By controlling the temperature and time of the thermal treatment, a clean and smooth substrate state is obtained. The effect of thermal treatment on the morphology and composition of GaSb substrate was analyzed by atomic force microscopy and X-ray photoelectron spectroscopy. The crystal quality of CdZnTe epitaxial film grown on GaSb substrate after thermal treatment was evaluated by double crystal X-ray curve. In order to further study the properties and epitaxial formation mechanism of the micro-defects near the heterogeneous interface, TEM analysis of CdZnTe/GaSb cross section was also carried out. After 180 s thermal treatment at 600 ℃, the GaSb substrate can obtain a clean and relatively flat surface after most of the oxide is removed from the substrate surface, thus improving the crystallization quality of CdZnTe epitaxial film. The full width of half maximum of double crystal X-ray curve is 94″, which approached the crystalline quality of bulk CdZnTe crystal ever reported.

Key words: CdZnTe, GaSb, epitaxial growth, thin film, physical vapour deposition, thermal treatment, semiconductor

中图分类号:

TN304.2

李阳, 曹昆, 介万奇. 热处理GaSb衬底对近距离升华法制备CdZnTe外延膜的影响[J]. 人工晶体学报, 2024, 53(10): 1705-1711.

LI Yang, CAO Kun, JIE Wanqi. Effect of Thermal Treated GaSb Substrate for Epitaxial Growth of CdZnTe Film by Close-Spaced Sublimation Method[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(10): 1705-1711.

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