Growth of CdTe by organometallic vapor phase epitaxy in an impinging jet reactor

Abstract

Deposition of (100)CdTe epilayers by organometallic vapor phase epitaxy (OMVPE) has been investigated using a vertical downward flowing impinging jet reactor with dimethylcadmium (DMCd) and diethyltelluride (DETe) as the organometallic sources. An Arrhenius plot of deposition rate versus substrate temperature had a linear region over a wide temperature range from 320 to 480 °C, corresponding to an activation energy for growth of 18 kcal/mol. Surfaces of (100)CdTe epilayers had high densities of pyramidal hillocks. Double-crystal x-ray rocking curves, however, were not affected by the presence of the hillocks. Full widths at half maximum for the (400) reflection of less than 30 arcsec were obtained for growth temperatures from 400 to 480 °C. At 460 °C rocking curves for the epilayer were nearly identical to the substrate demonstrating that films whose quality matches that of the underlying substrate can be deposited in the impinging jet system.