Characterization of Indium Segregation in Metalorganic Vapor Phase Epitaxy-Grown InGaP by Schottky Barrier Height Measurement

Abstract

Surface/interface segregation of indium in InGaP layers grown by metalorganic vapor phase epitaxy has been studied. Al/InGaP Schottky barrier height (ΦB) measurement was used for the evaluation of the segregation. It is shown that ΦB of GaAs/InGaP/GaAs double heterostructure (DH) is larger than that of InGaP/GaAs single heterostructure (SH), suggesting the diffusion of indium into upper GaAs layer. It is shown that the indium segregation progresses at the initial stage of InGaP growth and saturates when the InGaP thickness reaches about 15 nm. Using the segregation model, we calculated the exchange coefficient of indium as 0.76 at 620 °C.