Defect reduction of Zn_xCd_yMg_1-x-ySe based structures grown on InP by using Zn irradiation of the III–V surface

The quality of lattice-matched Zn_xCd_yMg_1-x-ySe epitaxial layers and related quantum well laser structures grown on (001) InP substrates has been improved by using Zn irradiation of the III–V surface before the growth of II–VI materials. The full widths at half maximum of the double crystal x-ray rocking curves for Zn_xCd_yMg_1-x-ySe epilayers with band gaps as high as 3.0 eV were reduced to about 50 arcsec. The defect density evaluated from the etch pit density and cathodoluminescence measurements was reduced from 10⁶ to mid-10⁴ cm^-2. This result suggests that an initial reaction between Se and group-III (In and Ga) atoms is a main limit to the quality of Zn_xCd_yMg_1-x-ySe grown on InP and the problem can be suppressed by using initial Zn irradiation of the III–V surface. © 1999 American Vacuum Society.