A CU SEED LAYER FOR CU DEPOSITION ON SILICON

A novel copper deposition method has been developed in which the solut ion is composed of hydrofluoric acid and cupric sulfate. Here, we inve stigate the growth mechanism of Cu film on silicon. The copper film th ickness is dominated by copper ion diffusion in the solution and, henc e, follows a parabolic relation with deposition time and a linear rela tion with copper ion concentration. In addition, we study the Cu depos ited on a silicon strip, which shows an isotropic etching property wit h an undercut against the mask. Furthermore, the deposited Cu on silic on shows a Schottky diode behavior. Its Schottky barrier height, leaka ge current and ideality factor are all studied in this paper. (C) 1997 Elsevier Science Ltd.