The Effect of Film Thickness on Mechanical Properties of TiN Thin Films

摘要

The effect of film thickness on property variation of TiN thin film is investigated in this study. The curve-fitting method is used for determining the mechanical properties of thin film deposited on substrate. The relationship between the load-deformation and material properties during the microindentation loading and unloading processes is simulated by employing the strain-hardened, elasto-plastic finite element model. The elastic and plastic material properties of thin film, i.e., Young's modulus, yield strength and strain-hardening exponent are extracted by applying an iterative curve-fitting scheme to the experimental and simulated force-indentation depth curves. The proposed method is applied to determine the variation of mechanical properties of TiN thin films with thicknesses ranging from 0.2 to 1.4 μm deposited on Si substrates. The extracted film material parameters also compared with literature data. In general, it is found that the Young's modulus of the TiN thin films reduces as the film thickness decreases. The reduction in the Young's modulus is particularly apparent in films with a thickness of less than 0.8 μm.