Progress in LPE Growth of HgCdTe at Kunming Institute of Physics

The recent progress in the LPE growth of HgCdTe(MCT) epi-layer at the Kunming Institute of Physics (KIP) is reported. The precipitates and inclusion density of the CdZnTe substrate are less than 5×10³ cm⁻² and the etch pit density (EPD) is less than 4.0×10⁴ cm⁻². Owing to the oriented growth technology of the CdZnTe single crystal with ϕ=120 mm, the variation of the Zn components in the prepared substrate wafers with ϕ=120 mm (111) was less than 0.36%. The maximum size of the HgCdTe films grown by LPE was up to 70 mm×75 mm, with an etch pit density (EPD) of 5×10⁴ cm⁻² and DCRC-FWHM less than 35 arcsec (could be lower than 25 arcsec). Over a substrate area of 50 mm×60 mm, the thickness homogeneity of the LPE MCT epi-layer is better than Δ_d=±1.25 μm, and a cut-off wavelength homogeneity better than Δ_λ=±0.1 μm is achieved for the LWIR MCT epi-layers; that of the MWIR epi-layers are ±1 μm and ±0.05 μm, respectively. Due to the improvement of material technology, which effectively increases the yield of low-cost MCT IRFPAs at KIP, high-performance LW/VLW/HOT IRFPAs and large array detectors such as 2048×2048 and 4096×4096 based on MCT/CZT have been developed.