Optimization of group V switching times for InGaP/GaAs heterostructures grown by LP-MOCVD

We studied the effect of group V switching times on the formation of interfacial layers in InGaP/GaAs heterostructures grown by LP-MOCVD using low temperature photoluminescence (PL), double crystal x-ray diffraction (DCXRD) and high resolution transmission electron microscopy (HR-TEM). Due to the severe substitution process of P by As, the quality of InGaP-to-GaAs interface was very sensitive to switching times. By optimizing the switching conditions, we were able to minimize the interfacial layers to one monolayer (ML) of In(0.5)G(0.5)As at the GaAs-to-InGaP interface and 1 ML of In0.65Ga0.35P0.15As0.85 at the InGaP-to-GaAs interface. Heterojunction bipolar transistors (HBTs) grown using this switching scheme showed excellent etch selectivity as well as de characteristics.