Effect of substrate misorientation on surface morphology of homoepitaxial CdTe films grown by organometallic vapor phase epitaxy

Abstract

The effect of substrate misorientation on surface morphology of CdTe homoepitaxial films deposited by organometallic vapor phase epitaxy was investigated by deposition onto a substrate polished in the shape of a spherical cap that exposed misorientations up to 15° from the [100] pole. Hillock formation was suppressed for misorientations between 2.5° and 4.5° from the [100] pole towards the nearest {111} Te planes, whereas tilt towards the nearest {111}Cd planes resulted in only a slight improvement in surface morphology. A commonly used direction for misorienting substrates, towards the nearest {110} planes, reduced the size and density of the hillocks but did not completely suppress their formation. Double-crystal x-ray rocking curves indicated that high crystalline quality was obtained near the (100) plane, and that misorientations towards the nearest {111}Te planes did not significantly degrade the quality. Arguments have been developed to rationalize these observations.