Universal interface growth in substrate etching processes

Abstract

Etching is a process that has been used both in art and in industry for hundreds of years. Although well understood on larger spatial scales, when acting on a smallscale two-dimensional lattice, more intricate effects seem to take place. This project has aimed at using a Monte Carlo simulation to study etching on a honeycomb lattice and describing the effect of the underlying crystal structure on the evolution of the system with different relative decay rates for solitary atoms. The implementation shows that at short times the crystal structure very much plays a role in the shapes that develop by creating shapes resembling a hexagon with slightly rounded corners. As time passes, the holes created become more circular, and especially for increasing reactivity for solitary atoms, the shape becomes nearly completely circular at large times. This is quantified by several metrics such as area error measurement as well as radial error measurements. We find that the radius grows linearly with time, indicating that as more atoms become exposed, more reactions occur, but as the interface grows larger, more atoms need to be annihilated to increase the radius. In future work, we would like to study longer time frames for more reactive conditions to see where the hexagonal error will plateau.