The measurement of doping profiles in thick epitaxial layers of GaP using Schottky barrier C- V data

Abstract

Using a Schottky diode technique investigations have been made of the variation in carrier concentration through epitaxial layers of GaP grown by liquid epitaxy and vapour transport methods using tellurium, sulphur and zinc as principal dopants. In all cases it is found that the carrier concentration alters significantly over the thickness of the grown layer and in some cases by as much as two orders of magnitude. The measured values of Hall concentration in the layers are weighted towards the higher levels of doping and are often not indicative of surface carrier concentration. This creates difficulties in trying to predict the electrical properties of epitaxial p- n junction diodes from Hall measurements alone.