It was shown that  suitable pit-patterning of a Si(001) substrate could strongly influenced the nucleation and the propagation of dislocations during epitaxial deposition of Si-rich Si1-xGex alloys, preferentially gettering misfit segments along pit rows. In particular, for a 250 nm layer deposited by molecular beam epitaxy at xGe = 15%, extended film regions appeared free of dislocations, by atomic force microscopy, as confirmed by transmission electron microscopy sampling. This result was quite general, as explained by dislocation dynamics simulations, which revealed the key role of the inhomogeneous distribution in stress produced by the pit-patterning.

Misfit Dislocation Gettering by Substrate Pit-Patterning in SiGe Films on Si(001). M.Grydlik, F.Boioli, H.Groiss, R.Gatti, M.Brehm, F.Montalenti, B.Devincre, F.Schäffler, L.Miglio: Applied Physics Letters, 2012, 101[1], 013119