CdZnTe中富碲沉积相缺陷引起的液相外延HgCdTe薄膜表面缺陷

Surface defects of Liquid Phase Epitaxial growth of HgCdTe film induced by Te-rich precipitates in CdZnTe substrates

为了研究液相外延碲镉汞薄膜表面缺陷形成机制,采用光刻工艺结合化学腐蚀方法在碲锌镉衬底表面实现了网格化,研究了碲锌镉近表面富碲沉积相与外延薄膜表面缺陷的关系.结果表明:衬底近表面富碲沉积相会导致碲镉汞薄膜表面孔洞、类针形凹陷坑缺陷以及三角形凹陷坑聚集区;在液相外延过程中,高温碲镉汞熔液与CdZnTe衬底间的回熔作用可以减少与富碲沉积相相关的表面缺陷,薄膜表面缺陷与衬底表面富碲沉积相的匹配度与回熔深度负相关;回熔过程以及富碲沉积相形态、深度影响HgCdTe薄膜表面缺陷形态和分布.

Correlation between surface defects on Liquid Phase Epitaxial(LPE)growth of HgCdTe films and Te-rich precipitates in CdZnTe substrates were studied.Results shown that three kinds of surface defects of LPE growth of HgCdTe film are as follows:surface crater defects,pinhole-like defects and concave pits,which related to the Te-rich precipitates in CdZnTe substrates.Substrate remelting process during LPE growth of HgCdTe film can reduced these defects.There was the negative correlation between the depth of the remelting layer and the matching of the surface defects and the Te-rich precipitates.The remelting of substrate surface layers during the LPE process affect the number and morphologies of HgCdTe surface defects,as well as the depth and the morphologies of the Te-rich precipitates.