Roughness effects on the thermal stability of thin films

In this work, we investigate interface roughness effects on the energetic terms that play a key role on the thermal stability of thin silicide films. The roughness is modeled as a self-affine structure with power spectrum ∼σ2ξ2(1+aq2ξ2)−1−H convoluted with a domain size distribution ∝e−πR2/ζ2 to account for grain finite size effects in polycrystalline films. The parameters σ, ξ, H, and ζ denote respectively the rms roughness, the roughness correlation length, the roughness exponent, and the average domain size. The roughness effect becomes significant for small H (<0.5), and large long-wavelength roughness or σ/ξ(∼0.1). Indeed, in systems where agglomeration occurs via thermal grooving, roughness may increase significantly the critical grain sizes.