Observation of metal on Si(001) by STM/STS and its consideration based on the first principles calculations

Local density of states (LDOS) is obtained by the first principles calculat ion based on the density functional theory on the Si(0 0 1)2 x 1 surface an d on the surface with an Al dimer. At an Al dimer, LDOS has a high intensit y in the conduction band region, which cannot be seen on the Si(0 0 1)2 x 1 surface. This tendency is observed in STS measurements as well. The possib ility for a microelementary analysis is presented by applying this method t o other metal atoms on the Si surface. Furthermore, it is pointed out that STS measurements should be always performed at the same tip-sample separati on to obtain reproducible STS spectrums. (C) 1999 Elsevier Science B.V. All rights reserved.