Surface structures of Ni-deposited Si(110) after annealing at various tempe
ratures have been investigated using scanning tunneling microscopy (STM). A
fter deposition of a few monolayers (ML) of Ni at room temperature, Ni clus
ters cover the surface homogeneously, where initial stripe patterns of up a
nd down terraces, characteristic of Si(110)-"16 x 2", are still visible. Af
ter annealing above 400 degrees C, NiSi2 islands with (1 x 1) periodicity g
row on the Si substrate showing various Ni-induced reconstructions. Detaile
d STM images of the surface of the islands have revealed that paired bright
protrusions are randomly distributed on the (1 x 1) terrace. We have propo
sed a structural model where adjacent Si atoms in the NiSi2(110) surface fo
rm dimers in the [001] direction forming a (1 x 1) terrace, on which pairs
of dimers are located at geometrically identical sites on the next grown Ni
Si2 layer.