Papers by Author: Peter G. Muzykov

Abstract: The effect of various types of in-grown stacking faults and threading screw/edge type dislocations on carrier lifetime and diffusion lengths in 4H-SiC epitaxial films was investigated through cathodoluminescence decays and charge collection efficiencies of electron beam induced current signals at specific defects sites. Most stacking faults yielded ~40% reduction in the carrier lifetime. Moreover, drastic lifetime reductions were observed in regions containing surface triangular defects and bulk 3C polytype inclusions. Dislocations of both types serve as efficient recombination centers, though stronger reduction in diffusion lengths was observed in the vicinity of screw type dislocations.

Abstract: In this work the analysis of thermal diffusion of boron carried out from vapor phase was performed. Two-branch diffusion associated with kick-out and substitution mechanisms was observed. The activation energy and prefactor were calculated from Arrhenius plot for each diffusion branch. It has been established that the surface layer of diffused boron mostly consists of shallow boron acceptors, while the tail of the diffusion profile has mostly deep level D centers.

Abstract: In this work we identified the nucleation sites of inverted pyramid defects in 4H-SiC epilayers using AFM and KOH etching and proposed a mechanism for its formation. Partial dislocations, bounding the stacking faults, mostly aligned along the <11-20> directions, were found at the base of the inverted pyramid defects. It is shown that the basal plane dislocations, serve as nucleation centers for stacking faults, and eventually the formation of inverted pyramid defects. A geometrical model is formulated to explain the formation mechanism of inverted pyramid defects.

Abstract: Triangular defects and inverted pyramid type defects formed during homoepitaxial growth on 4H-SiC Si face, 4° off-cut towards [11-20] direction have been investigated. Growth parameters responsible for triangular defect formation were identified and optimized for its reduction in this study. It was found that although the high temperature reduces the density of inverted pyramid type defects, it is not the only remedy for reducing their density and cleanliness of susceptor along with the initial growth condition plays a major role in the formation of these defects.