【摘要】 研究了利用GaAs作为衬底的HgCdTe MBE薄膜的表面缺陷,发现其中一类缺陷与Hg源中杂质有关。采用SEM对这类缺陷进行正面和横截面的观察,并采用EDX对其正面和横截面进行成分分析。并设计了两个实验:其一,在CdTe/GaAs衬底上,低温下用Hg源照射20min,再在其上继续高温生长CdTe;其二,在CdTe/GaAs衬底上,一直用Hg源照射下高温生长CdTe。两个实验后CdTe表面都出现与HgCdTe表面相比在形状和分布上类似的表面缺陷,采用光学显微镜和SEM对CdTe表面缺陷进行了观察,通过CdTe表面缺陷和HgCdTe表面缺陷的比较,我们证实了这类表面缺陷的成核起源于Hg源中杂质。更多还原

【Abstract】 The surface defects on MBE-grown HgCdTe films on GaAs substrates were studied,and there was a type of defects that relates to the impurities from mercury source.Faces and cross-sections of the defects were observed by using SEM,and the component analysis was performed by using EDX.Two experiments were designed: one was growing CdTe film on CdTe/GaAs substrate with high temperature,after the substrate with low temperature exposed on Hg flux in 20min;the other was growing CdTe film on CdTe/GaAs substrate with high temperature,being exposed on Hg flux all along in the CdTe growth.The defects that were similar in shape and distribution to those on the surfaces of HgCdTe films appeared on surfaces of CdTe films after two experiments,and the defects on the surfaces of two CdTe films were observed by using SEM.By comparing the defects on the surfaces of two CdTe films with the defects on the surfaces of HgCdTe films,we finally confirmed the fact that the impurities from mercury source resulted in the nucleation of this type of surface defects on HgCdTe films.更多还原