昆明物理研究所分子束外延碲镉汞薄膜技术进展

Progress in MBE Growth of HgCdTe at Kunming Institute of Physics

碲镉汞(MCT)自从问世以来一直是高端红外(IR)探测器领域的首选材料,分子束外延碲镉汞技术具有低成本异质外延、材料能带精准调控、原位成结等优势,是第三代红外焦平面陈列(FPA)器件研制的重要手段。本文报道了昆明物理研究所分子束外延(MBE)MCT薄膜技术进展,包括材料结构、晶体质量、表面缺陷、材料均匀性、掺杂浓度等参数优化控制的研究结果。异质衬底、碲锌镉衬底上MCT薄膜尺寸分别为4英寸(10.16 cm)及2.5 cm×2.5 cm,材料EPD值分别在1×106 cm^-2附近及(3~30)×104 cm^-2范围,表面宏观缺陷密度分别在30 cm^-2附近及100~300 cm^-2范围,薄膜质量与国内外先进水平相当。采用分子束外延MCT薄膜实现了2048×2048中波红外(MWIR)、2048×2048短波甚高分辨率红外(SWIR)焦平面、640×512中短双色红外(S-MWIR)、320×256中中双色红外(M-MWIR)FPA探测器的研制和验证。

HgCdTe(MCT)has dominated the high performance end of the IR detector market for decades.Owing to many merits,including the possibility of using low cost alternative substrates such as Ge and Si,precisely energy band structure control,and device structure grown,molecular beam epitaxy(MBE)growth of MCT has become the main tool for fabricating third generation IR focal plane arrays(FPA).Recent progress in MBE growth of MCT at Kunming Institute of Physics(KIP)is reported,including results in structure design,crystalline quality control,surface macro-defect control,cut-off wavelength and thickness uniformity control,doping control.For MCT on alternative and CdZnTe substrate,the maximum size are 4-inch(10.16 cm)and 2.5 cm×2.5 cm,the EPD are around 1×106 cm^-2 and in the range of(3~30)×104 cm^-2,the macro-defect density are around 30 cm^-2 and between(1~3)×102 cm^-2,respectively.Single color MWIR 2048×2048 detector,SWIR 2048×2048 detector,dual-band S-MWIR 640×512 detector,and dual-band M-MWIR 320×256 FPA detector are fabricated and demonstrated using MBE MCT.