INTERACTION OF CAVITIES WITH MISFIT DISLOCATIONS IN SIGE SI HETEROSTRUCTURES/

Consequences of the strong, short-range attractive interaction between cavities and misfit dislocations are examined in SiGe/Si heterostruct ures. When He is implanted at the SiGe/Si interface, either in situ du ring epitaxial growth or by post-growth treatment, cavities form and l ocate on the misfit dislocation cores, The misfit dislocations are no longer straight lines extending over several microns, but form a netwo rk with jogs and intersections at the cavities. The He-implanted cavit y layer enhances thermal relaxation of the strained alloy and may incr ease the achievable degree of relaxation by lowering dislocation energ ies.