p-N junction depth profiling and conductivity type determination using Auger electron spectroscopy

A novel method of p‐n junction determination is developed. The method is based on Auger line shift monitoring during Auger depth profiling of p‐n junctions in semiconductors using ion sputtering. The energy shifts of Auger lines are caused by surface cathodo‐electromotive forces—an analogue of surface photo‐electromotive forces but induced by electron bombardment. The possibilities and limitations of the method are studied by its application to p‐n junction depth profiling in Si, GaAs and InP and also in heterostructures made on the basis of AlGaAs alloys. The depth resolution of the method is found to depend on the sputtering dose needed to reach the p‐n junction and it is limited by diffusion of electrically active defects produced by ion bombardment. This limitation of the method makes it productive in evaluating the p‐n junctions located at submicron depths from the surface. For such junctions it provides better depth resolution than the electrical methods.