  Monte Carlo simulations of the colloidal epitaxy of hard spheres (HSs) on a
square pattern have been performed. This is an extension of previous
simulations; we observed a shrinking intrinsic stacking fault running in an
oblique direction through the glide of a Shockley partial dislocation
terminating its lower end in fcc (001) stacking [Mori et al., Molec. Phys. 105
(2007) 1377], which was an answer to a question why the defect in colloidal
crystals reduced by gravity [Zhu et al., Nature 387 (1997) 883]. We have
resolved one of shortcomings of the previous simulations; the driving force for
fcc (001) stacking, which was stress from a small periodic boundary simulation
box, has been replaced with the stress from a pattern on the bottom. We have
observed disappearance of stacking fault in this realizable condition. Sinking
of the center of gravity has been smooth and of a single relaxation mode under
the condition that the gravitational energy mgd is slightly less than the
thermal energy kT. In the snapshots tetrahedral structures have appeared often,
suggesting formation of staking fault tetrahedra.
