Abstract:
A method of growing planar non-polar m-plane Ill-Nitride material, such as an m- plane gallium nitride (GaN) epitaxial layer, wherein the Ill-Nitride material is grown on a suitable substrate, such as an m-plane Sapphire substrate, using hydride vapor phase epitaxy (HVPE). The method includes in-situ pretreatment of the substrate at elevated temperatures in the ambient of ammonia and argon, growing an intermediate layer such as an aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN) on the annealed substrate, and growing the non-polar m-plane Ill-Nitride epitaxial layer on the intermediate layer using HVPE. Various alternative methods are disclosed.
Abstract:
A method for growing on a substrate strongly aligned uniform cross-section semiconductor composite nanocolumns is disclosed. The method includes: (a) forming faceted pyramidal pits on the substrate surface; (b) initiating nucleation on the facets of the pits; and; (c) promoting the growth of nuclei toward the center of the pits where they coalesce with twinning and grow afterwards together as composite nanocolumns. Multi-quantum-well, core-shell nanocolumn heterostructures can be grown on the sidewalls of the nanocolumns. Furthermore, a continuous semiconductor epitaxial layer can be formed through the overgrowth of the nanocolumns to facilitate fabrication of high-quality planar device structures or for light emitting structures.
Abstract:
A method has been developed to overcome deficiencies in the prior art in the properties and fabrication of semi-polar group III-nitride templates, films, and materials. A novel variant of hydride vapor phase epitaxy has been developed that provides for controlled growth of nanometer-scale periodic structures. The growth method has been utilized to grow multi-period stacks of alternating AlGaN layers of distinct compositions. The application of such periodic structures to semi-polar III-nitrides yielded superior structural and morphological properties of the material, including reduced threading dislocation density and surface roughness at the free surface of the as-grown material. Such enhancements enable to fabrication of superior quality semi-polar III-nitride electronic and optoelectronic devices, including but not limited to transistors, light emitting diodes, and laser diodes.
Abstract:
A method of growing planar non-polar m-plane or semi-polar III- Nitride material, such as an m-plane gallium nitride (GaN) epitaxial layer, wherein the Ill-Nitride material is grown on a suitable substrate, such as an m-plane Sapphire substrate, using hydride vapor phase epitaxy (HVPE). The method includes in-situ pretreatment of the substrate at elevated temperatures in the ambient of ammonia and argon, growing an intermediate layer such as an aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN) on the annealed substrate, and growing the non-polar m-plane III- Nitride epitaxial layer on the intermediate layer using HVPE.