Patterned substrate design for layer growth

摘要

A patterned surface for improving the growth of semiconductor layers, such as group III nitride-based semiconductor layers, is provided. The patterned surface can include a set of substantially flat top surfaces and a plurality of openings. Each substantially flat top surface can have a root mean square roughness less than approximately 0.5 nanometers, and the openings can have a characteristic size between approximately 0.1 micron and five microns.

主权项

1. A device comprising:
a substrate comprising a patterned surface, wherein the patterned surface includes a set of substantially flat top surfaces and a plurality of openings, wherein each substantially flat top surface has a root mean square roughness less than approximately 0.5 nanometers, wherein the plurality of openings have a characteristic size between approximately 0.1 micron and five microns, wherein the substrate is an at least partially transparent layer, and wherein the substrate includes an outer surface having a profiled surface, the profiled surface including:
a set of large roughness components providing a first variation of the profiled surface having a characteristic scale approximately an order of magnitude larger than a target wavelength of the radiation; anda set of small roughness components providing a second variation of the profiled surface having a characteristic scale on the order of the target wavelength of the radiation, wherein the set of small roughness components are superimposed on the set of large roughness components.