Site selectivity in the reaction of Si(111)-(7×7) with Si₂H₆

We find that the reaction of disilane with the Si(111)-(7×7) surface shows strong site selectivity. The reaction involves the fission of the Si-Si bond of Si2H6 even at low temperatures and occurs preferentially at rest-atom sites of the 7×7 surface. The reaction of the products of the thermal dissociation of the surface-bound SiHx groups with surface dangling-bond sites is also site selective. We propose mechanisms to explain the above observations. © 1990 American Chemical Society.