On the Young modulus of 304 L stainless steel thin films

The sputter-deposited 304-L stainless steel (SS) films on bulk substrates ( glass, silicon, steel) generally present large residual stresses that cause debonding of the film from the substrate (stress relaxation) when the film thickness exceeds 500 nm. Although this phenomenon is undesirable for futu re technological applications, one may take benefit of it for intrinsic mec hanical property characterization of the film. In that way, the buckling ge ometry analysis allows determination of the Young's modulus of the film whe n the in-plane residual stress is known. In this paper, we applied, with su ccess, this method to extract the Young's modulus of 600-nm thick 304 L SS films. The value obtained indicates a decrease of 30% of the film modulus w ith respect to bulk steel. (C) 2000 Elsevier Science Inc. All rights reserv ed.