MBE HgCdTe on Si and GaAs substrates

This paper describes some recent results on the growth of HgCdTe on alternative substrates of GaAs and Si, and presents preliminary results on focal plane arrays (FPAs) applications. The quality of HgCdTe grown on Si was found to be identical to that grown on GaAs. The X-ray double-crystal rocking curve (XDRC) full-width at half-maximum (FWHM) values varied in a range of 55–75 arcsec (corresponding to the EPD values of 1–5×106 cm−2) for HgCdTe grown on Si or GaAs. The densities of surface defects were reduced to the levels below 300 and 500 cm−2 for HgCdTe grown on GaAs and on Si, respectively. A mean FWHM value of 64.1 arcsec with a standard deviation of 4.3 arcsec was obtained on HgCdTe (10 μm) grown on CdTe (8.6 μm)/Si, and a mean value of 53.9 arcsec with a standard deviation of 2.2 arcsec was obtained on HgCdTe (11.4 μm) grown on CdTe (12.3 μm)/GaAs. The maximum radical deviation of x values across the 3 in HgCdTe epilayers was less than 0.003, corresponding to a deviation of cutoff wavelengths at 80 K of less than 0.09 μm for MW and 0.25 μm for LW samples, respectively. The performance of FPAs fabricated on HgCdTe grown on Si was found to be similar to that on GaAs.