Pulsed growth of catalyst-free growth of GaN nanowires and application in group III nitride semiconductor bulk material
Exemplary embodiments provide semiconductor devices including high-quality (i.e., defect free) group III-N nanowires and uniform group III-N nanowire arrays as well as their scalable processes for manufacturing, where the position, orientation, cross-sectional features, length and the crystallinity of each nanowire can be precisely controlled. A pulsed growth mode can be used to fabricate the disclosed group III-N nanowires and/or nanowire arrays providing a uniform length of about 10 nm to about 1000 microns with constant cross-sectional features including an exemplary diameter of about 10-1000 nm. In addition, high-quality GaN substrate structures can be formed by coalescing the plurality of GaN nanowires and/or nanowire arrays to facilitate the fabrication of visible LEDs and lasers. Furthermore, core-shell nanowire/MQW active structures can be formed by a core-shell growth on the nonpolar sidewalls of each nanowire.
1. A nanowire array comprising:
a support comprising a plurality of surface regions and a selective growth mask disposed over a substrate, wherein a buffer layer comprising one or more of GaN, AIN, InN, InGaN, AllnGaN or AlGaN is disposed between the substrate and the selective growth mask, wherein each of the plurality of surface regions has a cross-sectional size and comprises a group III-N nanowire nucleus;
a group III-N nanowire extending from each of the plurality of surface regions of the support, wherein each group III-N nanowire is oriented along a same crystallographic direction, maintains a cross-sectional size that corresponds to the size of the surface region, and has a length of about 10 nm or greater.
2. A nanowire array comprising:
a support comprising a plurality of surface regions and a selective growth mask disposed over a substrate, wherein each of the plurality of surface regions has a cross-sectional size and comprises a group III-N nanowire nucleus, wherein each group III-N nanowire nucleus comprises a pyramid-shaped group III-N nanostructure disposed thereon and is interspersed in the selective growth mask, and wherein a top facet of the pyramid-shaped group III-N nanostructure provides one of the plurality of surface regions; and
a group III-N nanowire extending from each of the plurality of surface regions of the support, wherein each group III-N nanowire is oriented along a same crystallographic direction, maintains a cross-sectional size that corresponds to the size of the surface region, and has a length of about 10 nm or greater.
3. A nanowire array comprising:
a support comprising a plurality of surface regions, wherein each of the plurality of surface regions has a cross-sectional size;
a group III-N nanowire extending from each of the plurality of surface regions of the support to form the nanowire array, wherein each group III-N nanowire is oriented along a same crystallographic direction, maintains a cross-sectional size that corresponds to the size of the surface region, and has a length of about 10 nm or greater; and
a group III-N substrate structure coalesced from the nanowire array, wherein the group HI-N substrate structure comprises GaN.
4. A nanowire array comprising:
a support comprising a plurality of surface regions, wherein each of the plurality of surface regions has a cross-sectional size;
a group III-N nanowire extending from each of the plurality of surface regions of the support to form the nanowire array, wherein each group III-N nanowire is oriented along a same crystallographic direction, maintains a cross-sectional size that corresponds to the size of the surface region, and has a length of about 10 nm or greater; and
a multiple quantum well (MQW) active structure disposed on at least a portion of each group III-N nanowire of the nanowire array, wherein the MOW active structure comprises a plurality of shells formed of lnGaN, AIGaN or GaN.