Optimisation of Epitaxial Layer Growth with HCl Addition by Optical and Electrical Characterization
High growth rate of 4H-SiC epitaxial layers can be reached with the introduction of HCl in the deposition chamber. The effect of the Cl/Si ratio on this epitaxial growth process has been studied by optical and electrical measurements. Optical microscopy shows an improvement of the surface morphology and luminescence measurements reveal a decrease of epitaxial layer defects with increasing the Cl/Si ratio in the range 0.05–2.0. The leakage current measured on the diodes realized on these wafers is reduced of an order of magnitude and DLTS measurements show a decrease of the EH6,7 level concentration in the same range of Cl/Si ratio. The value Cl/Si=2.0 allows to grow epitaxial layers with the lowest defect concentration.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
L. Calcagno et al., "Optimisation of Epitaxial Layer Growth with HCl Addition by Optical and Electrical Characterization", Materials Science Forum, Vols. 556-557, pp. 137-140, 2007