Three-Dimensional Diamond MPCVD Growth over MESA Structures: A Geometric Model for Growth Sector Configuration

Abstract

The overgrowth of {100}-oriented patterned diamond substrates by microwave plasma enhanced chemical vapor deposition was studied by transmission electron microscopy through a stratigraphic approach. A sector-like growth behavior is evidenced, resulting from a competition between slowly growing facets at protruding (top) corners and edges against quickly growing facets at recessing (bottom) corners. Depending on the pattern orientation and height, under some particular experimental conditions, it is possible to predict the sequence of growth sectors, and thus to choose the crystallographic orientation of the overgrown surface, by stopping the growth at the right stage. A simple two-dimensional model is provided, allowing the fabrication of structures adapted to the requirements of specific electronic devices.