Microhardness properties of Cu-W amorphous thin films

Pure copper, pure tungsten and amorphous Cu50W50 and Cu66W34 alloy films we re deposited by the direct current magnetron sputtering technique on cooled glass substrates. The film microhardness has been investigated as a functi on of alloy composition and substrate potential bias during deposition. The microhardness exhibited a maximum at Cu concentrations close to 50 at%, si milar to the case of completely miscible binary alloys. The ion bombardment caused by the negative substrate polarization increased the film microhard ness. The annealing of the amorphous Cu-W films up to 250 degrees C in vacu um increased the film microhardness by 10-20% apparently owing to the forma tion of the W(Cu) crystalline phase dispersed within a predominantly amorph ous film matrix. (C) 1998 Kluwer Academic Publishers.