Since bifurcation is not yet automated in our code, we initialized this geometry as slightly bifurcated already, and track the result. We specifically show the initial hole, shown from below, without triangle edges as well as the etched hole, showing only the edges and curves, but not the surface. In this way it is possible to make a geometric comparison. A striking feature is the tapering at the bottom, correctly predicted through the solution of Riemann problems. Resputtering, i.e., the non sticking of the incoming material, is one of the main mechanisms for the creation of undesigned voids in a computer chip.
Voids therefore contribute to overheating, and thus shorten the chip's lifetime.
The sticking probability is taken as 0.8. Although a point source this close to the chip's surface is somewhat unphysical its effect is quite similar to area source whose particle beam widens with distance. During this simulation the region near the top of the hole has grown to close the hole, the point where this simulation ended. Shown is a side view, with the initial hole, tightened into a single, pink, dot.