Some observations on the dislocation etching of GaAs 1-χP χ epitaxial layers

Abstract

The structure of GaAs 1-χP χ epitaxial layers containing up to 45 mol% GaP has been revealed by dislocation etching of {111} crystal planes. This technique has the important advantage of enabling the whole structure of the epitaxial layer to be examined simultaneously. The effect of varying the thickness of the compositionally graded region on the crystal perfection of the constant composition region is shown. Use of this technique has led to the finding that variations in the HCl flow (as well as the AsH 3 and PH 3 flows) cause a change in the crystal composition.