采用分子束外延(Molecular Beam Epitaxy,MBE)法制备了高质量的npn型中波/中波双色HgCdTe材料.利用傅里叶变换红外光谱仪(Fourier Transform Infrared Spectrometer,FTIR)、二次离子质谱(Secondary Ion Mass Spectroscopy,SIMS)、X 射线双晶衍射仪(X-Ray double-crystal Diffractometer,XRD)分别测试了材料组分、厚度、元素分布和平均半峰宽等参数.结果表明,材料底部n型吸收层的碲镉汞组分为0.318,厚度为7.15 μm;p型层的组分为0.392,厚度为2.47 μm;顶部n型吸收层的组分为0.292,厚度为4.71μm.As掺杂浓度约为3 × 1018 cm-3,In掺杂浓度为4× 1015 cm-3,平均半峰宽约为95 arcsec,表明该材料具有良好的质量.利用聚焦离子束(Focused Ion Beam,FIB)、扫描电子显微镜(Scanning Electron Microscope,SEM)、X 射线能谱仪(Energy-Dispersive X-ray spectrometer,EDX)测试表征了 HgCdTe外延材料表面缺陷的形貌,确认缺陷主要受生长温度和Hg/Te束流比等生长参数的影响.
Study on Medium-Wave/Medium-Wave Two-Color HgCdTe Materials by Molecular Beam Epitaxy
High-quality npn medium-wave/medium-wave two-color HgCdTe materials were prepared by mo-lecular beam epitaxy.Fourier transform infrared spectroscopy(FTIR),secondary ion mass spectroscopy(SIMS)and X-ray double-crystal diffractometer(XRD)were used to test the material composition,thickness,element distribution,average half-peak width and other parameters.The results show that the HgCdTe com-position of the bottom n-type absorption layer is 0.318 with a thickness of 7.15 μm,the composition of the p-type layer is 0.392 with a thickness of 2.47 μm,and the composition of the top n-type absorption layer is 0.292 with a thickness of 4.71 μm.The As doping concentration is about 3×1018 cm-3,the In doping concen-tration is 4×1015 cm 3,and the average half-peak width is about 95 arcsec,indicating that it has good quality.The surface defects of the HgCdTe epitaxial layer were characterized by focused ion beam(FIB),scanning e-lectron microscope(SEM)and energy-dispersive X-ray spectrometer(EDX)tests.It is confirmed that the de-fects are mainly related to growth parameters such as growth temperature and Hg/Te beam-current ratio.
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