Effect of threading screw and edge dislocations on transport properties of 4H–SiC homoepitaxial layers

Abstract

Local recombination properties of threading screw and edge dislocations in 4H-SiC epitaxial layers have been studied using electron beam induced current ͑EBIC͒. The minority carrier diffusion length in the vicinity of dislocations was found to vary with dislocation type. Screw dislocations had a more pronounced impact on diffusion length than the edge dislocations, evidencing stronger recombination activity. Temperature dependence of EBIC contrast of dislocations suggests that their recombination activity is controlled by deep energy levels in the vicinity of dislocation cores. This paper shows that the type of dislocation ͑screw or edge͒ can be identified from analysis of EBIC contrast.

Traps in 4H-SiC Field-Effect Transistors Characterized by Capacitance- and Current-Mode Deep-Level Transient Spectroscopy

“…For example, dislocations are a common type of crystallographic defect in SiC, and local recombination properties of threading screw and edge dislocations in 4H-SiC epitaxial layers have been studied using electron beam-induced current (EBIC). 21 In that study, it was found that screw dislocations have a more pronounced impact on diffusion length than edge dislocations, promoting stronger recombination. Moreover, the temperature dependence of the EBIC contrast near dislocations suggested that the recombination activity was controlled by deep centers in the vicinity of the dislocation cores.…”

Effect of residual stress on the electrical activity of dislocations in GaN light emitting diodes

“…The correction factor describes the combined effect of dislocation position, carrier generation, carrier diffusion, and bulk and surface recombination velocities in the surrounding defect free region on EBIC contrast. [14,15]. Because F is associated with the defect free regions, F is a constant for a given sample, and all of the variation is described by c in (3).…”

Degradation of 4H-SiC IGBT threshold characteristics due to SiC/SiO2 interface defects

“…SiC, on the otherhand, is being exploited for high-power device structures because of its higher thermal conductivity, larger band gap and higher electron mobility than Si [3][4][5][6][7][8][9][10][11]. The work of Weitzel et al [3] summarized the performances of a variety of SiC-based power devices.…”

“…Ref. [10] characterized threading edge and screw dislocations while Ref. [11] presented propagation behavior of threading dislocations in SiC crystals.…”