Abstract: Boron-containing compounds, gasses and fluids are used during ammonothermal growth of group-Ill nitride crystals. Boron-containing compounds are used as impurity getters during the ammonothermal growth of group-Ill nitride crystals. In addition, a boron-containing gas and/or supercritical fluid is used for enhanced solubility of group-Ill nitride into said fluid.

Abstract: A method for controlling the relative and absolute growth rates of all possible crystallographic planes of a group-III nitride crystal during ammonothermal growth. The growth rates of the various exposed crystallographic planes of the group-III nitride crystal are controlled by modifying the environment and/or conditions within the reactor vessel, which may be subdivided into a plurality of separate zones, wherein each of the zones has their own environment and conditions. The environment includes the amount of atoms, compounds and/or chemical complexes within each of the zones, along with their relative ratios and the relative motion of the atoms, compounds and/or chemical complexes within each of the zones and among the zones. The conditions include the thermodynamic properties each of the zones possess, such as temperatures, pressures and/or densities.

Abstract: A method for adding hydrogen-containing and/or nitrogen-containing compounds to a nitrogen-containing solvent used during ammonothermal growth of group-Ill nitride crystals to offset decomposition products formed from the nitrogen-containing solvent, in order to shift the balance between the reactants, i.e. the nitrogen-containing solvent and the decomposition products, towards the reactant side.

Abstract: Reactor designs for use in ammonothermal growth of group-III nitride crystals envision a different relative placement of source materials and seed crystals with respect to each other, and with respect to the vessel containing a solvent. This placement results in a difference in fluid dynamical flow patterns within the vessel.

Abstract: A high-quality, large-area seed crystal for ammonothermal GaN growth and method for fabricating. The seed crystal comprises double-side GaN growth on a large-area substrate. The seed crystal is of relatively low defect density and has flat surfaces free of bowing. The seed crystal is useful for producing large-volume, high-quality bulk GaN crystals by ammonothermal growth methods for eventual wafering into large-area GaN substrates for device fabrication.

Abstract: The present invention includes a high-quality, large-area bulk GaN seed crystal for ammonothermal GaN growth and method for fabricating. The seed crystal is of ultra-low defect density, has flat surfaces free of bowing, and is free of foreign substrate material. The seed crystal is useful for producing large-volume, high-quality bulk GaN crystals by ammonothermal growth methods for eventual wafering into large-area GaN substrates for device fabrication.

Abstract: The present invention provides a method for growing group III-nitride crystals wherein the group III-nitride crystal growth occurs on an etched seed crystal. The etched seed is fabricated prior to growth using a temperature profile which produces a high solubility of the group III-nitride material in a seed crystals zone as compared to a source materials zone. The measured X-ray diffraction of the obtained crystals have significantly narrower Full Width at Half Maximum values as compared to crystals grown without etch back of the seed crystal surfaces prior to growth.

Abstract: A Group III-nitride semiconductor film containing aluminum, and methods for growing this film. A film is grown by patterning a substrate, and growing the Group III-nitride semi-conductor film containing aluminum on the substrate at a temperature designed to increase the mobility of aluminum atoms to increase a lateral growth rate of the Group III-nitride semiconductor film. The film optionally includes a substrate patterned with elevated stripes separated by trench regions, wherein the stripes have a height chosen to allow the Group III-nitride semiconductor film to coalesce prior to growth from the bottom of the trenches reaching the top of the stripes, the temperature being greater than 1075° C., the Group III-nitride semiconductor film being grown using hydride vapor phase epitaxy, the stripes being oriented along a (1-100) direction of the substrate or the growing film, and a dislocation density of the grown film being less than 107 cm?2.

Abstract: A method of obtaining a hexagonal würtzite type epitaxial layer with a low impurity concentration of alkali-metal by using a hexagonal würtzite substrate possessing a higher impurity concentration of alkali-metal, wherein a surface of the substrate upon which the epitaxial layer is grown has a crystal plane which is different from the c-plane.