ROUGHNESS EFFECTS ON THE THERMAL-STABILITY OF THIN-FILMS

In this work, we investigate interface roughness effects on the energe tic terms that play a key role on the thermal stability of thin silici de films. The roughness is modeled as a self-affine structure with pow er spectrum similar to sigma(2) xi(2)(1+aq(2) xi(2))(-1-H) convoluted with a domain size distribution proportional to e(-pi R2/xi 2) to acco unt for grain finite size effects in pori crystalline films. The param eters sigma, xi, H, and zeta denote respectively the rms roughness, th e roughness correlation length, the roughness exponent, and the averag e domain size. The roughness effect becomes significant for small H (< 0.5), and large long-wavelength roughness or sigma/xi(similar to 0.1). Indeed, in systems where agglomeration occurs via thermal grooving, r oughness may increase significantly the critical grain sizes. (C) 1997 American Institute of Physics.