Determination of junction depth and related current phenomena using laser beam induced current

摘要

The characterisation of photodiode junction depth using laser beam induced current (LBIC) has long been ambigious, due in part to the limited understanding behind the relevant physics governing this phenomena, and more importantly, the signal behaviour for the various device geometries. In this work, the induced current behaviour arising from the individual junction components that form the device for different geometric conditions is examined in detail. In particular, at low temperatures, the overall LBIC signal dependence to junction depth could be attributed to current crowding through the dominance of two competing current mechanims which include a lateral current, flow, I_(lbic), and a transverse current flow, I_(ph). This study represents another step in the development towards a fully quantitative procedure for extracting junction depth and alternatively interpreting the current contributions arising from the individual junction components using LBIC.