Surface smoothing of rough amorphous films by irradiation-induced viscous flow - art. no. 196106

Surface roughening and smoothing reactions on vapor codeposited glassy Zr65 Al7.5Cu27.5 films by 1.8 MeV Kr+ ion beam irradiation is investigated. Irra diation causes significant smoothing of initially rough surfaces, and nearl y atomically smooth films can be achieved. Smooth surfaces roughen at high doses and long wavelengths. By a Fourier analysis, radiation-induced viscou s flow is identified as the dominant surface relaxation mechanism. Two nois e terms are identified, which operate on different length scales: One is du e to sputtering and the other to thermal spikes. The irradiation-induced vi scosity is compared with radiation-enhanced diffusion.