Characterization of trapping states in semiconductors

Defect energy states within the band gap affect the performance of semiconductor response time. A characterization of defects to benefit diode performance was made. Characterization includes the energy differences from the band edge, and the capture cross section of the energy state. Deep Level Transient Spectroscopy (DLTS) a method using the transient capacitance properties of reverse-biased p-n junction diodes to characterize defects was studied using two different DLTS experimental setups. A complex model is proposed for the DX center consisting of a group plus an excited state with independent capture cross sections and communication between the two levels. Since classical analysis of DLTS data yielded misleading results when a complex trap was considered, a computer simulation and curve fitting technique was used to determine the trap structure and parameters. This technique gave values for the ground state energy, for the excited state, prefactor values on the ground, excited, and communication prefactor.