HETEROEPITAXY OF CDTE ON GE(211) SUBSTRATES BY MOLECULAR-BEAM EPITAXY

CdTe(2 1 1)B has been grown by molecular beam epitaxy (MBE) on (2 1 1) oriented germanium as an alternative substrate. Germanium was chosen from among several alternative substrate candidates in order to circum vent the weaknesses of the CdTe homosubstrate. CdTe heteroepitaxy was studied for several germanium substrate orientations. The best CdTe gr owth condition occurs on (2 1 1) oriented germanium substrate. This or ientation offers the compatibility required for MBE HgCdTe growth and is the orientation commonly used. The surface morphology of CdTe layer s with a diameter of two inches is smooth and mirror-like. The crystal line quality was measured by an X-ray double-crystal rocking curve on {4 2 2} planes. The best full width at half maximum (FWHM) is as low a s 75 arcsec. A FWHM map is presented showing a good crystalline unifor mity. Transmission electron microscopy (TEM) and secondary ion mass sp ectrometry (SIMS) characterizations are also presented. (C) 1998 Elsev ier Science B.V. All rights reserved.