A Continuum Model For the Morphology of Regrown GaAs Gratings Derived from Atomic Scale Processes
Abstract
We have developed a set of continuum equations that couples the interaction between the surface adatom population and the surface in epitaxial growth. This model explains the complex shape evolution observed in regrowth on micronscale GaAs gratings as a function of film thickness and growth temperature. The equations are rooted in the physical processes at the surface: adatom diffusion and step edge attachment and detachment. Interlayer transport is driven by an inverse Schwoebel barrier, which tends to push the adatoms downhill. In the limit of weak surface texture, the continuum model reduces to the Edwards-Wilkinson equation, with a smoothing coefficient that depends directly on the step edge barrier and the growth flux. We speculate that the higher order terms in this expansion can be approximated by the Kardar-Parisi-Zhang nonlinearity.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARB33002B