Convenient Determination of Concentration and Energy in Deep-Level Transient Spectroscopy

For defects or impurities with deep energy levels, such as the commonly observed EL2, EL3, and EL6 in GaAs, it is very important to take account of the so‐called λ effect in order to deduce the correct concentrations of these centers when using capacitance techniques. By measuring capacitance at several forward bias voltages for a given reverse bias voltage it is possible to determine concentration NT and energy ET without requiring the usual emission rate analysis. Convenient formulas for NT and ET are given, although only NT can be determined with a high degree of precision. The results for an n‐type horizontal Bridgman wafer (n≂2.8×1016 cm−3) are: NEL2=(1.14±0.02)×1016 cm−3, EEL2(377 K)=0.71±0.06 eV; NEL6=(8.0±0.5)×1015 cm−3, EEL6(167 K)=0.42±0.09 eV