Patterned layer design for group III nitride layer growth

摘要

A device having 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.

主权项

1. A device comprising:
a first layer having a patterned surface, wherein the patterned surface includes a top surface having a root mean square roughness less than approximately 0.5 nanometers and a plurality of openings in the top surface that form a lateral hexagonal arrangement, wherein each of the plurality of openings has a diameter between approximately 0.1 microns and approximately five microns and a depth of at least 0.2 microns; and a second layer directly on the patterned 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 diameter of the openings.