Smoothening by Self-Diffusion of Silicon during Annealing in a Rapid Processing Chamber

Abstract

Atomic-scale mechanisms of thermal activated self-diffusion on crystal surfaces are investigated through AFM images. Surface evolution is studied by means of the Power Spectral Density (PSD) function over a large spatial bandwidth. We propose a parametric model based on the Mullins-Herring (MH) diffusion equation by adding two stochastic terms. Then, surface evolution during high temperature annealing in reducing ambient can be predicted. Very good agreement between experimental and theoretical roughness and diffusion parameters was observed. Origin and evolution of the stochastic terms, describing conservative and non-conservative noises, are discussed.