Dependence of Morphology on Miscut Angle for Si(111) Etched in NH(4)F
S Gonda, Joseph Fu, John A. Kramar, Richard M. Silver, Hui Zhou
Using scanning probe microscopy, we have examined the surfaces produced by etching several different vicinal Si(111) samples in NH(4)F aqueous solution. In agreement with others, we found that deoxygenation of the etchant generally reduces the number of triangular etch pits. We also found that for maximum uniformity and minimum roughness, a certain minimum miscut angle is required. This angle is related to the maximum clear terrace width, which in turn is related to the relative etching rate of the step-edge sites and the terrace sites.