A GaN-on-Si device structure and a method of fabrication are disclosed for improved die yield and device reliability of high current/high voltage lateral GaN transistors. A plurality of conventional GaN device structures comprising GaN epi-layers are fabricated on a silicon substrate (GaN-on-Si die). After processing of on-chip interconnect layers, a trench structure is defined around each die, through the GaN epi-layers and into the silicon substrate. A trench cladding is provided on proximal sidewalls, comprising at least one of a passivation layer and a conductive metal layer. The trench cladding extends over exposed surfaces of the GaN epi-layers, over the interface region with the substrate, and over the exposed surfaces of the interconnect layers. This structure reduces risk of propagation of dicing damage and defects or cracks in the GaN epi-layers into active device regions. A metal trench cladding acts as a barrier for electro-migration of mobile ions.

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.

A phosphor plate includes a plate-like composite including a base material and a phosphor contained in the base material, in which the base material contains spinel, the phosphor includes a phosphor containing a Si element, and in an X-ray diffraction pattern of the phosphor plate using a Cu-Kα ray, in a case in which peak intensity corresponding to the spinel having a diffraction angle 2θ in a range of 36.0° or more and 37.4° or less is set to 1, total intensity of peaks having a diffraction angle 2θ in a range of 32.5° or more and 34.5° or less satisfies 0.5 or less.

Provided is a high-pressure reactor suitable for a high-pressure process using supercritical ammonia grow bulk crystal of group III nitride having lateral dimension larger than 2 inches or to form various transition metal nitrides. The reactor has nutrient distributed along the reactor's longitudinal axis and seed material positioned at the reactor's inner wall and along the reactor's longitudinal axis. Nutrient diffuses through supercritical ammonia from the reactor's longitudinal axis and deposits on the seed material positioned by the reactor's inner wall. Both the nutrient and seed material are heated by the same heater. Material growth can primarily be due to material diffusion through supercritical ammonia. This configuration and methodology reduce convective movement of supercritical ammonia due to temperature differential, providing a more quiescent environment in which group III nitride or transition metal nitride is formed.

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 μm, 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.

The present invention relates to a method for producing monocrystalline gallium containing nitride from a source material containing gallium in the environment of supercritical ammonia solvent with the addition of a mineralizer containing the element of Group I (IUPAC, 1989), wherein in an autoclave two temperature zones are generated, i.e. a dissolution zone with lower temperature containing the source material, and a crystallization zone located below it with higher temperature, containing at least one seed. At least two further components are introduced into the process environment, namely an oxygen getter in molar ratio to ammonia ranging from 0.0001 to 0.2, and an acceptor dopant in molar ratio to ammonia not higher than 0.1, said acceptor dopant being manganese, iron, vanadium or carbon, or a combination thereof. The invention also relates to a monocrystalline gallium containing nitride prepared by this method.

The object of the present invention is to provide a large-sized gallium nitride-based sintered body having a small oxygen amount and high strength, a large-sized gallium nitride-based sintered body having a small oxygen amount and containing a dopant, to obtain a highly crystalline gallium nitride thin film which has become a n-type or p-type semiconductor by a dopant, and methods for producing them.

A gallium nitride-based sintered body, which has an oxygen content of at most 1 atm % and an average particle size (D50) of at least 1 μm and at most 150 μm.

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 0≤x≤1, 0≤y≤1, 0≤x+y≤1), and the concentration of B in the crystal is less than 1×10.sup.15 at/cm.sup.3, and each of the concentrations of O and C in the crystal is less than 1×10.sup.15 at/cm.sup.3 in a region of 60% or more of a main surface.

A sputtering target for a gallium nitride thin film, which has a low oxygen content, a high density and a low resistivity. A gallium nitride powder having powder physical properties of a low oxygen content and a high bulk density is used and hot pressing is conducted at high temperature in high vacuum to prepare a gallium nitride sintered body having a low oxygen content, a high density and a low resistivity.

There is provided a nitride crystal substrate constituted by group-III nitride crystal, containing n-type impurities, with an absorption coefficient α being approximately expressed by equation (1) by a least squares method in a wavelength range of at least 1 μm or more and 3.3 μm or less.

[00001]$\begin{array}{cc}\alpha =N_{e}K{\lambda }^a\left(\mathrm{where}1.5\times {10}^{-19}\le K\le 6.0\times {10}^{-19},a=3\right),& \left(1\right)\end{array}$ here, a wavelength is λ (μm), an absorption coefficient of the nitride crystal substrate at 27° C. is α (cm.sup.−1), a carrier concentration in the nitride crystal substrate is N.sub.e (cm.sup.−3), and K and a are constants, wherein an error of an actually measured absorption coefficient with respect to the absorption coefficient α obtained from equation (1) at a wavelength of 2 μm is within +0.1α, and in a reflection spectrum measured by irradiating the nitride crystal substrate with infrared light, there is no peak with a peak top within a wavenumber range of 1,200 cm.sup.−1 or more and 1,500 cm.sup.−1 or less.