Effect of Additional Silane on In Situ H2 Etching prior to 4H-SiC Homoepitaxial Growth
We have investigated the influence of in-situ H2 etching on the surface morphology of the 4H-SiC substrate prior to homoepitaxial growth. In this study, we varied the types of gas atmosphere during in-situ H2 etching; namely, hydrogen (H2) alone, hydrogen-propane (H2+C3H8), and hydrogen-silane (H2+SiH4). We found that in-situ H2 etching using H2 + SiH4 significantly improved the surface morphology of 4H-SiC substrate just after in-situ H2 etching. By adding SiH4, formation of bunched step structure during in-situ H2 etching could be significantly suppressed. In addition, H2 etching using H2 + SiH4 was able to remove scratches by etching a thinner layer than that using H2 alone. We also discussed the in-situ H2 etching mechanism under the additional SiH4 condition.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
K. Kojima et al., "Effect of Additional Silane on In Situ H2 Etching prior to 4H-SiC Homoepitaxial Growth", Materials Science Forum, Vols. 556-557, pp. 85-88, 2007