Typical grain growth occurs in a polycrystalline phase under the constraint of constant volume, resulting in reduction of the total surface (grain boundary) area and energy. The grain growth rate is parabolic. We present here a different kind of grain growth in thin films during deposition, while the film is thickening. The grain growth rate can be linear. In vapor-phase deposition of face-centered-cubic metals such as Al and Cu, the grain size of the film is known to be nearly the same as the film thickness. A linear grain growth rate is expected if the deposition rate is constant. If we assume the grain size to be the same as the thickness, the total surface (grain boundary) area does not change. Under the constraint of a constant surface area, we present here a simple kinetic model of linear rate of grain growth during film deposition. We define it as flux-driven grain growth. A Monte Carlo simulation has been performed for comparison, and the results show a linear relationship between grain size and film thickness.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 10 Jun 2003|