Step Formation on Hydrogen-Etched 6H-Sic{0 0 0 1} Surfaces


Nie, S., Lee, C. D., Feenstra, R. M., Ke, Y., Devaty, R. P., Choyke, W. J., … & Gu, G. (2008). Step formation on hydrogen-etched 6H-SiC {0 0 0 1} surfaces. Surface Science, 602(17), 2936-2942.


The formation of step bunches and/or facets on hydrogen-etched 6H-SiC(0 0 0 1) and (0001¯) surfaces has been studied, using both nominally on-axis and intentionally miscut (i.e. vicinal) substrates. It is found that small miscuts on the (0 0 0 1) surface produce full unit-cell high steps, while half unit-cell high steps are observed on the (0001¯) surface. The observed step normal direction is found to be 〈11¯00〉 for both surfaces. Hence, for intentionally miscut material, a miscut oriented towards this direction produces much better order in the step array compared to a miscut oriented towards a 〈112¯0〉 direction. For (0 0 0 1) vicinal surfaces that are miscut towards the 〈11¯00〉 direction, the formation of surface ripples is observed for 3° miscut and the development of small facets (nanofacets) is found for higher miscut angles. Much less faceting is observed on miscut (0001¯) surfaces. Additionally, the (0 0 01) surface is found to have a much larger spatial anisotropy in step energies than the (0001¯) surface.

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