Electrical and Optical Characterization of Intrinsic and Ion-Implantation Induced Defects in 6H- and 4H-SiC

摘要

Deep level transient spectroscopy (DLTS), Hall effect, and cathodolummescence (CL) measurements are used to characterize the intrinsic and ion-implantation induced defects in high-temperature (475 and 500 deg C) ion- implanted epitaxial n-type 6H- and 4H-SiC, ion-implanted with Cr, Mg, Ar, N, and P atoms. Comparison of room-temperature and high-temperature ion-implanted 6H- SiC:Mg and :Cr indicate the significance of high-temperature ion implantation on the activation of the ion-implanted atoms and damage-recovery of the crystalline lattice. The effects of high-temperature annealing on both damage-recovery and implanted ion activation are detected and analyzed, from 1200 to 1800 degrees C. Trap parameters 0 both damage-related and species-related defects are determined by curve-fitting of DLTS rate window plots, including the identification of a 615 meV silicon-vacancy- substitutional-nitrogen defect. Double-correlated DLTS measurements indicate a one-dimensional distribution of various defects along the implantation axis and slight surface diffusion of ion-implanted magnesium during high-temperature annealing. Current-voltage- temperaturemeasurements of 6H-SiC:Mg :Cr indicate the effect of annealing temperature and ion species on the concentration of near midgap defects.Optimum anneal temperatures are determined for activation of ion-implanted nitrogen and phosphorus. CL measurements indicate the formation of deep radiative centers in 500 degrees C ion-implanted 4H-SiC:P and :N. CL measurements also indicate the presence of a 130 meVhigher energy level conduction band minimum.