Effects of the AsCl[sub 3] Mole Fraction on the Incorporation of Germanium, Silicon, Selenium, and Sulfur into Vapor Grown Epitaxial Layers of GaAs

Abstract

The effect of the mole fraction on the incorporation of germanium, silicon, selenium, and sulfur in epitaxial layers has been studied. The layers were grown by vapor phase epitaxy (VPE) using the synthesis system. Both room‐ and low‐temperature Hall data as well as photoluminescence spectra were used to examine the incorporation of the impurities into grown layers. The results of these studies indicate that the incorporation of silicon and germanium decreases with increasing mole fraction, and that the incorporation of sulfur and selenium is largely unaffected by changes in the mole fraction. The results are interpreted using a model which proposes that the major background dopant in this system is silicon and that the mole fraction effect is due to the interaction of stable chlorides of silicon with hydrogen chloride in the reactor. A calculation of the activity of silicon as a function of the hydrogen chloride pressure is presented. The results compare reasonably well with the experimental data.