Surfactant Effects on Ordering in GaInP Grown by Omvpe

Abstract

AbstractCuPt ordering in III/V semiconductor alloys is significant because of the dependence of bandgap energy on degree of order. This paper presents the effects of surfactants isoelectronic with P on ordering in GaInP grown by organometallic vapor phase epitaxy. Each of the three surfactants studied, As, Sb, and Bi, is found to result in disordering for layers grown using conditions that would otherwise produce highly ordered materials. The amount of surfactant required in the vapor phase (as the organometallic precursors TMAs, TESb, and TMBi) increases as the volatility of the group V element increases. Thus, the amount of TEAs required to produce disordered GaInP is approximately two orders of magnitude greater than for TMBi.For Sb, the disordering is shown to be caused by a replacement of [110 ] P dimers on the nominally (001) surface by Sb dimers with the same orientation. For Bi, a marked change in the step structure coincides with the loss of order. For singular (001) substrates, island formation is suppressed by Bi.