An STM study of Cu on Si(001) in the c(8 x 8) structure

We have studied the growth of Cu on the Si(001) surface over a range of gro wth temperatures and metal coverages. The only ordered phase seen by low en ergy electron diffraction (LEED), other than the 2 x 1 substrate pattern, w as a c(8 x 8) phase which occurs at coverages as low as 0.05 monolayers. Sc anning tunneling microscopy (STM) measurements show that the c(8 x 8) struc ture consists of an array of bright features, two per unit cell. We propose one possible atomic structure on the basis of the STM images. (C) 2000 Els evier Science B.V. All rights reserved.