Extremely reproducible zinc diffusion into InSb and its application to infrared detector array

A systematic investigation has been performed on diffusion of Zn in n-type InSb using elemental Zn and Sb in closed ampoules at temperature range 355–455 °C. The diffusion behavior could be well understood by arranging the data as a function of the mole ratio of Sb to Zn in the source, Nsb/Nzn. The diffusion depth was constant, independing on the total amount of Zn or/and Sb source loaded into ampoule when Nsb/Nzn≤0.5 or Nsb/Nzn ≥5, if Zn source was enough. When Nsb/Nzn ≥5, a highly planar diffusion front and a high quality p-type layer were reproducibly obtained. However, when Nsb/Nzn ≤ 0.5, a very ragged diffusion front and much damage were observed. 3–5 μm InSb photovoltaic detector arrays with 8 elements were prepared using above results.