Gallium-containing nitride crystals are disclosed, comprising: a top surface having a crystallographic orientation within about 5 degrees of a plane selected from a (0001) +c-plane and a (000-1) c-plane; a substantially wurtzite structure; n-type electronic properties; an impurity concentration of hydrogen greater than about 510.sup.17 cm.sup.3; an impurity concentration of oxygen between about 210.sup.17 cm.sup.3 and about 110.sup.20 cm.sup.3; an [H]/[O] ratio of at least 0.3; an impurity concentration of at least one of Li, Na, K, Rb, Cs, Ca, F, and CI greater than about 110.sup.16 cm.sup.3; a compensation ratio between about 1.0 and about 4.0; an absorbance per unit thickness of at least 0.01 cm.sup.1 at wavenumbers of approximately 3175 cm.sup.1, 3164 cm.sup.1, and 3150 cm.sup.1; and wherein, at wavenumbers between about 3200 cm.sup.1 and about 3400 cm.sup.1 and between about 3075 cm.sup.1 and about 3125 cm.sup.1, said gallium-containing nitride crystal is essentially free of infrared absorption peaks having an absorbance per unit thickness greater than 10% of the absorbance per unit thickness at 3175 cm.sup.1.

In a gallium nitride crystal, a nanovoid density in the crystal is less than 110.sup.5 [cm.sup.2]. A crystal growth apparatus is an apparatus for manufacturing a gallium nitride crystal, wherein a member having a B concentration of less than 1 ppm at least at a surface part is used as a member used at a part where a temperature is 500 C. or higher (high-temperature member) among members exposed to a crystal growth space. When such a crystal growth apparatus is used, a gallium nitride crystal wherein a nanovoid density in the crystal is less than 110.sup.5 [cm.sup.2] is obtained.

An epitaxial structure and a method for making the same are provided. The epitaxial structure includes a substrate, an epitaxial layer and a carbon nanotube layer. The epitaxial layer is located on the substrate. The carbon nanotube layer is located in the epitaxial layer. The method includes following. A substrate having an epitaxial growth surface is provided. A carbon nanotube layer is suspended above the epitaxial growth surface. An epitaxial layer is epitaxially grown from the epitaxial growth surface to enclose the carbon nanotube layer therein. The epitaxial layer is a substantially homogenous material from the substrate.

A process of preparing polycrystalline group III nitride chunks comprising the steps of (a) placing a group III metal inside a source chamber; (b) flowing a halogen-containing gas over the group III metal to form a group III metal halide; (c) contacting the group III metal halide with a nitrogen-containing gas in a deposition chamber containing a foil, the foil comprising at least one of Mo, W, Ta, Pd, Pt, Ir, or Re; (d) forming a polycrystalline group III nitride layer on the foil within the deposition chamber; (e) removing the polycrystalline group III nitride layer from the foil; and (f) comminuting the polycrystalline group III nitride layer to form the polycrystalline group III nitride chunks, wherein the removing and the comminuting are performed in any order or simultaneously.

A high-quality nitride crystal can be produced efficiently by charging a nitride crystal starting material that contains tertiary particles having a maximum diameter of from 1 to 120 mm and formed through aggregation of secondary particles having a maximum diameter of from 100 to 1000 m, in the starting material charging region of a reactor, followed by crystal growth in the presence of a solvent in a supercritical state and/or a subcritical state in the reactor, wherein the nitride crystal starting material is charged in the starting material charging region in a bulk density of from 0.7 to 4.5 g/cm.sup.3 for the intended crystal growth.

There is provided a nitride crystal substrate made of a nitride crystal with a diameter of 100 mm or more, having on its main surface: a continuous high dislocation density region and a plurality of low dislocation density regions divided by the high dislocation density region, with the main surface not including a polarity inversion domain.

This disclosure provides a vapor-liquid reaction device including a vapor-liquid reaction chamber and a projecting member. The vapor-liquid reaction chamber holds a molten metal in a lower portion of an internal space of the vapor-liquid reaction chamber.

An object of the present invention is to improve quality of a nitride crystal, and also improve performance and manufacturing yield of a semiconductor device manufactured using the crystal. Provided is a nitride crystal in which a composition formula is represented by In.sub.xAl.sub.yGa.sub.1-x-yN (satisfying 0x1, 0y1, 0x+y1), and the concentration of B in the crystal is less than 110.sup.15 at/cm.sup.3, and each of the concentrations of O and C in the crystal is less than 110.sup.15 at/cm.sup.3 in a region of 60% or more of a main surface.

Systems and methods for growth of multi-component single crystals are described. A first solution is flowed over a surface of a seed crystal coupled to a nozzle such that a plurality of first ions solvated in the first solution and a plurality of second ions in a second solution combine on the surface of the seed crystal to grow the single-crystal thereon. The first solution and the second solution are immiscible. A feed tank is fluidly coupled to the at least one nozzle and includes the first solution. In some aspects, the nozzle is configured to flow both the first solution and the second solution over the seed crystal.

The present invention is directed to crystalline solids having an empirical formula of M.sub.2A.sub.2X, wherein M is at least one Group IIIB, IVB, VB, or VIB metal, preferably Cr, Hf, Sc, Ti, Mo, Nb, Ta, V, Zr, or a combination thereof; wherein A is Al, Ga, Ge, In, Pb, or Sn, or a combination thereof; and each X is C.sub.xN.sub.y, where x+y=1. In some particular embodiments, the crystalline composition has a unit cell stoichiometry of Mo.sub.2Ga.sub.2C.