We report the results of a study of the structural properties of Co films deposited on Cu/H-Si(110). A Cu(lll) buffer layer is formed by evaporation or ultrahigh vacuum sputter deposition on the H-terminated Si(110) surface. From consideration of bulk lattice constants, the Cu films undergo a 6% expansion along the [1, -1, 0] direction and a 13% compression along the [1, 1, -2] direction. The structure and annealing behavior of the Cu buffer layer was determined with a combination of low-energy electron diffraction (LEED) and Auger electron spectroscopy. The LEED patterns of Co films evaporated on this buffer layer are compared to Co films grown on a Cu(lll) single crystal. (C) 2000 American Vacuum Society. [S0734-2101(00)03304-2].