A Cu seed layer for Cu deposition on silicon

A novel copper deposition method has been developed in which the solution is composed of hydrofluoric acid and cupric sulfate. Here, we investigate the growth mechanism of Cu film on silicon. The copper film thickness is dominated by copper ion diffusion in the solution and, hence, follows a parabolic relation with deposition time and a linear relation with copper ion concentration. In addition, we study the Cu deposited on a silicon strip, which shows an isotropic etching property with an undercut against the mask. Furthermore, the deposited Cu on silicon shows a Schottky diode behavior. Its Schottky barrier height, leakage current and ideality factor are all studied in this paper. (C) 1997 Elsevier Science Ltd.