Mechanisms of growth and defect properties of epitaxial SiC

作者:La Via F*; Camarda M; La Magna A
来源:Applied Physics Reviews, 2014, 1(3): 031301.
DOI:10.1063/1.4890974

摘要

In the last ten years, large improvements in the epitaxial silicon carbide processes have been made. The introduction of chloride precursors, the epitaxial growth on large area substrate with low defect density, the improvement of the surface morphology, the understanding of the chemical vapour deposition (CVD) reactions, and epitaxial mechanisms by advanced simulations are just the main results obtained in the homo-epitaxy process of 4H-SiC. After this large stride in the process of SiC epitaxial growth, it is time to collect this knowledge in a review that can be a reference point for the future work in this interesting field. The structure of the review is the following. After an introduction on the evolution and history of the epitaxial growth of 4H-SiC, the main physics parameter of this epitaxial growth process is explained in detail using the traditional Burton-Cabrera-Franck theory and the experimental observations of the surface instability due to the off-axis growths. Then the introduction of chlorinated precursors in the epitaxial process is reviewed and the effect of this new process on Schottky diodes characteristics is shown. The improvement of the epitaxy process is strictly related to the improvement of the simulation of the growth that helps the researchers to understand the effect of different parameters on such complex system. Then, a large part of the review is devoted to the simulations of the CVD systems, the reaction in the gas phase of the different precursors and the surface reaction models. Also, some important results obtained by Monte Carlo simulation on the study of different growth parameters that influence the formation of defects and their evolution are reported. Finally, the influence of different process parameters and in particular of the growth rate on the formation or the reduction of the principal defects that are observed in the epitaxial layer is reviewed. We have divided these defects in four categories: 3D defects (epi-stacking faults and inclusions), 2D defects (stacking faults), 1D defects (dislocations), and 0D defects (point defects). Also the influences of the growth parameters on the surface morphology (step-bunching) and the correlation with defects have been reviewed. In the conclusions the main results on the chloride epitaxy has been summarized and an outlook of this process in the next years has been presented with the actual understanding of the mechanism of the silicon carbide epitaxial growth.

  • 出版日期2014-9