  Pattern formation on semiconductor surfaces induced by low energetic ion-beam
erosion under normal and oblique incidence is theoretically investigated using
a continuum model in form of a stochastic, nonlocal, anisotropic
Kuramoto-Sivashinsky equation. Depending on the size of the parameters this
model exhibits hexagonally ordered dot, ripple, less regular and even rather
smooth patterns. We investigate the transitional behavior between such states
and suggest how transitions can be experimentally detected.

Materials Science;Statistical Mechanics