Application of DLTS and Laplace-DLTS to defect characterization in high-resistivity semiconductors

摘要

This paper shows that the use of conventional analytical procedures to determine defect parameters from DLTS spectra may lead to erroneous results for high-resistivity semiconductors. The effect is observed when the temperature range of a DLTS peak encompasses the temperature at which the equilibrium Fermi level intersects the energy level of defect under study. Based on this Fermi level effect, a procedure is proposed to determine the occupancy levels for defects with a strong temperature dependence of the carrier capture cross-section. It has been found that the procedure can be useful for characterization of positive-U states through to negative-U centers in semiconductors.