Relation between Leakage Current in PIN Photodiodes and Defects in InGaAs(P)/InP Heterostructures Grown Low Pressure MOCVD

Abstract

ABSTRACTHigh resolution maps of the InGaAs photoluminescence intensity over whole 50mm diameter PIN detector wafers grown by low pressure MOCVD were obtained using a scanning photoluminescence (PL) system. The leakage current of PIN detectors was found to decrease exponentially with increased PL intensity. This correlation was quantitatively valid for both variation on a given wafer and for wafer-to-wafer variations. The density of morphological features on the surface of InGaAs(P)/InP heterostructures also was found to decrease exponentially with increased PL intensity, where a simple linear relationship between leakage current and feature density was then determined. The features are likely a manifestation of substrate defects which propagate from the surface of poor quality substrates.