Formation of regular step arrays on Si(111)7x7

Highly regular arrays of steps are produced on vicinal Si(111)7X7 surfaces. A tilt of the surface normal from (111) toward ((1) over bar (1) over bar 2) produces single steps (0.3 nm high and typically 15 nm apart). The opposite tilt toward (11 (2) over bar) produces bunched steps with adjustable height (1-5 nm) and a spacing of 70 nm. Preparation criteria for straight edges and regular spacings are determined, taking into account the miscut angle (azimuthal and polar), annealing sequence, current direction, and applied stress. (C) 1998 American Institute of Physics.