Stainless steel films deposited by de unbalanced magnetron sputtering using SUS304 steel target

We have deposited stainless steel films onto glass slides under various ion bombardment conditions by de unbalanced magnetron sputtering. The apparatus was equipped with an external coil around the magnetron cathode which allows us to alter the ion flux to the substrate. A commercial SUS304 steel disk (phi 50 mm x 2 mm) was used as a target. The sputtering gas was Ar (99.999%) and its pressure ranged from 0.2 to 1.0 Pa. The applied de power and external coil current were also varied in the range P-dc = 100 similar to 220 W and I-c = -3 similar to4 A, respectively. The crystal structure, composition, internal stress, corrosion resistance and hardness of deposited films were examined. The deposited films showed bcc structure with strong (110) preferred orientation. The film surface looks like martensite with very fine grain. The Cr composition in deposited films appeared to decrease about 2 mass% compared to target material. The ion bombardment showed very small effect on the structure and the composition of deposited films. The corrosion resistance and the hardness of the films seemed to be much better than bulk material.