碲锌镉衬底表面在碲镉汞液相外延工艺中的热腐蚀效应

摘要

该研究以提高液相外延碲镉汞材料的质量为出发点,研究液相外延生长过程中碲锌镉衬底受到高温汞蒸气影响后的变化情况,并利用光学显微镜、白光干涉仪、能谱仪等分析测试手段对碲锌镉衬底表面进行分析.研究结果表明,液相外延生长过程中,高温汞蒸气对碲锌镉衬底中表面沉淀物尺寸无明显影响,但在衬底表面发现两种类型的腐蚀点,一种是尺寸为25 μm左右的较大腐蚀点,分布较均匀;另一种是尺寸为7μm左右的圆形腐蚀点,分布不均匀.衬底经过液相外延薄膜成核生长前的温度变化过程以及高温Hg蒸气的作用,碲锌镉衬底表面形貌呈鱼鳞状,粗糙度增大了50％以上.%Influence of Hg vapor to CZT substrate during LPE growth of HgCdTe process were studied,CZT substrates were characterized by combining with Microscope,White-light Interferometer (WLI) and Energy Dispersive Spectrometer (EDS).Results show that the CZT substrates mainly suffered the Hg vapor during LPE process,Hg vapor has no effect on the precipitations in CZT substrates surface.Two kinds of typical Hg erosion defects are found on CZT substrates after Hg vapor treatment process.One is a kind of large defect that had size of 25 μm and distributed uniformly,while the other is smaller size of 7 μm presented nonuniform distribution.Furthermore,fish scale like surface morphology on CZT substrate is found after Hg vapor treatment process during LPE growth of HgCdTe,surface roughness increase more than 50％.