SPUTTER-DEPOSITED WBX FILMS

Films of WBx have been deposited on silicon and GaAs substrates from a compound target using an r.f. magnetron sputtering system to investigate the structural properties. A substrate bias has been applied to vary the deposition and film properties. Electrical resistivity, deposition rate and intrinsic film stress have been determined under various argon pressure and substrate bias conditions. As-deposited films are amorphous with resistivities of about 180ωμ cm. When annealed in a reducing atmosphere the films are found to be very stable. Crystallization starts at 840°C, as monitored by electrical resistance and X-ray diffraction patterns. The results are discussed on the basis of the binary phase diagram and empirical rules for the stability of amorphous phases, and the results are used to suggest that WBx films can be used as diffusion barriers. © 1990.