A method to determine deep level profiles in highly compensated, wide band gap semiconductors

A lighted capacitance-voltage (LCV) method for spatially profiling defect levels in wide band gap, highly compensated materials is presented. Combined with deep level optical spectroscopy, the optical nature of the LCV profiling technique enables the quantitative study of lower bounds of concentrations for multiple deep and midgap levels. Unlike many other approaches to measuring large deep level concentrations in resistive semiconductors, this LCV method requires no constant-capacitance feedback circuit and is applicable to wide band gap materials such as GaN and SiC. To demonstrate this technique, deep levels at E-c-3.0 and 3.28 eV are spatially profiled in heavily compensated GaN:C:Si Schottky diodes. Comparison of the profiles with conventional constant-capacitance and constant-voltage approaches for calculating deep level concentrations shows good agreement between the methods and demonstrates the validity of the technique. (C) 2005 American Institute of Physics.