Roughness evolution during chemical vapor deposition

Surface roughness with a broad range of scale that is not suitable for application in most cases is often produced during chemical vapor deposition (CVD). In this work, we survey the mechanisms causing roughness evolution during CVD from a phenomenological viewpoint. We classify roughness evolution processes into two stages, i.e., the initial stage of deposition on the substrate and the growth stage of continuous films. Thermodynamic and kinetic factors are discussed in the initial stage. In the growth stage, roughness evolution can be classified into two types: positive-feedback growth and non-positive-feedback growth. The former includes shadowing, concentration gradient, and preferential deposition of particles. The latter includes the effect of crystallographic planes, crystallinity, composition, and catalytic activities.