Step dynamics in relaxation of sharp corners on crystal surfaces

The dynamic behavior of steps involved in the relaxation of sharp corners in microfabricated structures on crystalline surfaces have been studied. We find that during the early stages of relaxation of slightly tapered trenches on Si(0 0 1), wide (1 1 0) terraces perpendicular to the substrate are formed near the corners of the trench sidewalls. The evolution of a step profile around the corner region, where step density abruptly changes, is analyzed using one-dimensional step models. It is found that, in case that mass transport occurs through surface diffusion, the preexisting steps on the trench sidewall are accumulated in the corner region, and extensive terraces are formed near the corners.