Patterned Layer Design for Group III Nitride Layer Growth

摘要

A method of fabricating a device using a layer with a patterned surface for improving the growth of semiconductor layers, such as group III nitride-based semiconductor layers with a high concentration of aluminum, is provided. The patterned surface can include a substantially flat top surface and a plurality of stress reducing regions, such as openings. The substantially flat top surface can have a root mean square roughness less than approximately 0.5 nanometers, and the stress reducing regions can have a characteristic size between approximately 0.1 microns and approximately five microns and a depth of at least 0.2 microns. A layer of group-III nitride material can be grown on the first layer and have a thickness at least twice the characteristic size of the stress reducing regions. A device including one or more of these features also is provided.

主权项

1. A device comprising:
a first layer having a substantially flat top surface with a root mean square roughness less than approximately 0.5 nanometers, wherein the substantially flat top surface includes a first plurality of openings, wherein the first plurality of openings have a characteristic size between approximately 0.1 microns and approximately five microns and a depth of at least 0.2 microns, and wherein the first plurality of openings are separated by a distance less than or equal to the characteristic size; and a second layer directly adjacent to the top surface of the first layer, wherein the second layer is a group III-nitride material having an aluminum concentration of at least seventy percent and having a thickness at least twice the characteristic size of the openings.