Steel symbol/number: M 350–50A/1.0810

Stress Study on CrN Thin Films with Different Thicknesses on Stainless Steel

“…Thermal stress depends on the thermal misfit led by the difference between film and substrate's CTE. Since CTE of the as-deposited film and substrates follows a relationship of a Si [18] \ a CrN [8] \ a Steel [17], the thermal stress in the CrN thin films on Si wafer and steel should consequently be tensile and compressive, respectively. Daniel et al [9] proved that the value of CrN's CTE tends to decrease as the film thickness increases, so the gap between a CrN and a Si would be wider for thicker films on steel, while the situation went the opposite way around on Si wafer.…”

“…with r the in-plane stress in the film, E s Young's modulus of the substrate, # s Poisson's ratio for the substrate (AISI 304 [17]: E steel = 180.5 GPa, # steel = 0.3, Si (001) [18]: E Si = 130 GPa, # Si = 0.28), h s thickness of the substrate, h f thickness of the film and R 1 =R 2 the radius of curvature of the substrate before/after deposition of the thin film, still remains the first choice, given the fact that the usually unknown elastic moduli of film are an indispensable parameter and the inevitable influence caused by the film thickness and texture when using X-ray diffraction sin2 w technique to evaluate residual stress [19]. Our previous work proposed a SCT method based on the measurement of sample movement distance D and laser spot movement distance L, and the following equation was employed to calculate the substrate curvature,…”