Influence of sputter deposition conditions on phase evolution in nitrogen-doped stainless steel films

In the present work, nitrogen-doped stainless steel (SS–N) films were deposited on Si (100) by reactive sputtering of an austenitic stainless steel target in argon and nitrogen gas mixtures under different conditions. The influence of several important parameters, such as nitrogen gas composition (%N2), substrate temperature, sputtering power density and target–substrate distance, on phase evolution in the film was studied. The results showed that a range of phases can evolve in the SS–N films. These include crystalline ferrite, amorphous S phase, crystalline S phase, CrN and the new cubic MN phase. The conditions for the formation of each of these phases were identified. In particular, the effect of the various deposition parameters on the formation of crystalline S phase is discussed in detail in this paper.