Diffusion Length Measurements Using Laser Beam Induced Current

The minority carrier diffusion length is a key indicator of material quality and gives an indication of n-on-p diode performance when the zero bias resistance is diffusion limited. In this study diffusion length is measured using a laser beam induced current technique, applied to a shallow p-n junction formed using standard diode junction formation conditions. Two dimensional modelling is used to examine the validity of results obtained using this geometry, as compared to the more standard diffusion length test structure geometries, which are more difficult to fabricate.