Effects of thermal annealing on HgCdTe/CdTe/Si(211) by MBE

Abstract

In this paper, the effects of thermal annealing (TA) were studied by theoretical calculation and experiment. The calculation was based on the Masafumi's model of dislocation movement, modified with thermal stress and lattice-mismatch in the HgCdTe/CdTe/Si(211) heterostructure. As the calculation indicated, the temperature and holding time of TA had great effect on the dislocation reduction, while less improvement with the epilayer thickness and growth orientation. Upon the result of calculation, the TA and thermal cycle annealing (TCA) experiments were performed under different conditions, which fit the calculation properly. The dislocation reduction of TA was investigated by double crystal X-ray rocking curve (DCRC) and etch pit density (EPD) measurements. The EPD of 10μm SW~LW HgCdTe/Si under optimized thermal process could be decreased half order of magnitude, with the lowest EPD at 2×10 6 cm -2 , as well as the full width at half maximum (FWHM) of the DCRC to 57.8 arcsec.