Influence of Crystal Growth Conditions on Nitrogen Incorporation During PVT Growth of SiC

摘要

The control and understanding of the incorporation of nitrogen during SiC PVT continues to play an important role in SiC crystal growth. Nitrogen acts both as a dopant and an impurity depending on the growth conditions and desired resistivity. Epitaxial growth by CVD provides some insight into N incorporation in terms of the face effects, temperature, and impact of the chemical species in terms of the C/Si ratio. This paper will present experimental results showing trends regarding nitrogen incorporation during SiC PVT. Various crystal growth processes operated under constant nitrogen partial pressures were found to produce wide ranges of SiC resistivity. These effects will be analyzed in light of the process impact on gas phase elemental composition (1), crystal stress (2), dopant activation (3) and crystal defectivity (4). The goal of this paper is to provide additional insights regarding nitrogen incorporation during SiC PVT, and in turn drive towards a more holistic approach to control the resistivity of 4H n+ SiC material, based on the understanding established from SiC epitaxy technology.