Surface reconstruction and faceting of group IIIIV(113) systems — common characteristics of the stable surface structures

In the present paper we report on studies of the group III/IV(113) systems of Al, Ga and In on Si(113) and Ge(113) with LEED and AES. LEED shows that after being annealed the surfaces of the Al/Si Ga/Si and In/Ge systems facet to (103), (013), (112) and (115) facets while those of the In/Si, Al/Ge and Ga/Ge systems reconstruct to (113)-(1 x 2). In the entire tested range of coverage and annealing temperature none of the six systems form (113)-(1 x 1). Combining this observation with the results of previous work on group III/IV(001) and group III/IV(111) we suggest that the common characteristics of all stable surface structures of the III/IV systems are: (i) the group 13 atoms form sp(2)-like back bonds, and (ii) the surface contains some group IV atoms with a dangling bond. The former is an intrinsic requirement of group III atoms, while the latter facilitates relief of the strain induced by the former, and is thus probably more general.