A NEW METHOD FOR DETERMINATION OF DEEP-LEVEL IMPURITY CENTERS IN SEMICONDUCTORS

Abstract

It is pointed out that the conventional capacitance method and the Copeland method provide different results for the determination of impurity concentrations of semiconductor wafers in the presence of deep centers. On the basis of a discussion of this phenomenon, a simple method of determining the concentration and the energy level of deep centers is proposed and demonstrated. The method is checked by application to oxygen-doped n-type GaAs with a carrier concentration of 3.2×1015 cm−3. The result yields a value of 2.1×1016 cm−3 for the deep center concentration and a value of 0.57 eV below conduction band for the energy level of the deep centers, which are reasonable in comparison with other experimental data.