Selective epitaxy of Si1-xGex/Si(100) via gas-source molecular beam epitaxy was carried out to compare facet formations in Si1-xGex to Si. A single {311} facet with a pronounced cusp at the intersection with the (100) surface was observed in large windows (25 mu m) However, facet formations occurring within smaller windows (less than or equal to 5 mu m) show the development of {311}- and {111}- type facets. For the 1-2 mu m features, no cusps were observed, and facet growth was initiated at an earlier stage of development, avoiding contact with the SiO2 mask. While a 1400 Angstrom Si epilayer is expected to have a {311}/{111} ratio of much less than one (similar to 0.15), for the 1-2 mu m windows, however, it is similar to 2. The persistence of the {311}-type facet offers a faster reduction of the original (100) surface that facilitates the fabrication of a nanoscale template.