Papers by Keyword: Hydrogen Etching

Abstract: We have proposed a novel model of hydrogen etching of SiC based on thermal equilibrium and have confirmed the validity of our model through the analysis of H2 etching experiments. The experimental results obtained showed that the etching rate is expressed by a linear equation with the H2 flow rate, by an exponential function with the reciprocal of the temperature and by a power law with the pressure. These results agree well with the theoretical behaviors derived from our model.

Abstract: This paper presents new observations resulting from in-situ high temperature hydrogen etching of 4H-SiC mesas that were step-free prior to initiation of etching. In particular, it was found that well-ordered pyramidal-shaped step train structures could be produced on mesa top surfaces via stepflow etching proceeding inward from the sides of mesas. In many cases, the height of steps etched inward from {112 0} mesa sides is 0.5 nm (2 Si-C bilayers), while the height of steps etched inward from {11 00} sides of the same mesa is 1.0 nm (4 Si-C bilayers, the repeat distance of the 4H-SiC polytype). We propose that stepflow etching starting from the mesa sidewall and involving step-to-step repulsive forces produces the observed step train structures.