A crystal growth apparatus includes: a raw material supplying part that mixes raw materials including a group III element metal and an alkali metal; a growing part disposed at a stage under the raw material supplying part, the growing part having a seed substrate; a tilting mechanism that tilts the raw material supplying part and the growing part; a heater that heats the raw material supplying part and the growing part; a control part that controls an operation of the tilting mechanism; and a supply port that supplies a nitrogen element-containing substance to the growing part, wherein the raw material supplying part having an opening facing to the growing part, the opening being disposed at a bottom portion and one edge portion of the raw material supplying part, and the control part controls the tilting mechanism so as to tilt the raw material supplying part toward the other edge portion on the side opposite to the one edge portion so as to prevent the raw materials from entering the opening when the raw materials are mixed, and the control part controls the tilting mechanism so as to tilt the raw material supplying part toward the one edge portion so that the raw materials drop through the opening to the growing part when the mixing of the raw materials is completed.

A vapor phase epitaxial growth device comprises a reactor vessel and a wafer holder arranged within the reactor vessel. The wafer holder includes a wafer holding surface configured to hold a wafer with a wafer surface oriented substantially vertically downward. The device comprises a first material gas supply pipe configured to supply a first material gas and arranged below the wafer holding surface. The device comprises a second material gas supply pipe configured to supply a second material gas and arranged below the wafer holding surface. The device comprises a gas exhaust pipe configured to exhaust gases and arranged below the wafer holding surface. A distance between the gas exhaust pipe and an axis line passing through a center of the wafer holding surface is greater than distances between the axis line and each of the first material gas supply pipe and the second material gas supply pipe.

An acoustic resonator comprises a first electrode, a second electrode and a piezoelectric layer disposed between the first electrode and the second electrode, and comprising a C-axis having an orientation. A polarization-determining seed layer (PDSL) is disposed beneath the piezoelectric layer, the seed layer comprising a metal-nonmetal compound. A method of fabricating a piezoelectric layer over a substrate comprises forming a first layer of a polarization determining seed layer (PDSL) over the substrate. The method further comprises forming a second layer of the PDSL over the first layer. The method further comprises forming a first layer of a piezoelectric material over the second layer of the PDSL; and forming a second layer of the piezoelectric material over the first layer of the piezoelectric material. The piezoelectric material comprises a compression axis (C-axis) oriented along a first direction.

Epitaxial growth methods and devices are described that include a textured surface on a substrate in a liquid crystal device. Geometry of the textured surface provides a organization of a liquid crystal media.

A periodic table Group 13 metal nitride crystals grown with a non-polar or semi-polar principal surface have numerous stacking faults. The purpose of the present invention is to provide a period table Group 13 metal nitride crystal wherein the occurrence of stacking faults of this kind are suppressed. The present invention achieves the foregoing by a periodic table Group 13 metal nitride crystal being characterized in that, in a Qx direction intensity profile that includes a maximum intensity and is derived from an isointensity contour plot obtained by x-ray reciprocal lattice mapping of (100) plane of the periodic table Group 13 metal nitride crystal, a Qx width at 1/300th of peak intensity is 6×10.sup.−4 rlu or less.

There is provided a method of manufacturing a group III nitride semiconductor substrate including: a fixing step S10 of fixing abase substrate, which includes a group III nitride semiconductor layer having a semipolar plane as a main surface, to a susceptor; a first growth step S11 of forming a first growth layer by growing a group III nitride semiconductor over the main surface of the group III nitride semiconductor layer in a state in which the base substrate is fixed to the susceptor using an HVPE method; a cooling step S12 of cooling a laminate including the susceptor, the base substrate, and the first growth layer; and a second growth step S13 of forming a second growth layer by growing a group III nitride semiconductor over the first growth layer in a state in which the base substrate is fixed to the susceptor using the HVPE method.

A C-plane GaN substrate only mildly restricts the shape and dimension of a nitride semiconductor device formed on the substrate. The variation of an off-angle on the main surface of the substrate is suppressed. In the C-plane GaN substrate: the substrate comprises a plurality of facet growth areas each having a closed ring outline-shape on the main surface; the number density of the facet growth area accompanied by a core among the plurality of facet growth areas is less than 5 cm.sup.−2 on the main surface; and, when any circular area of 4 cm diameter is selected from an area which is on the main surface and is distant by 5 mm or more from the outer peripheral edge of the substrate, the variation widths of an a-axis direction component and an m-axis direction component of an off-angle within the circular area is each 0.25 degrees or less.

Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.

The invention concerns a reactor for chemical vapour deposition from first and second precursor gases, the reactor comprising: —a chamber including top and bottom walls and a side wall linking the top and bottom walls, —a support intended for receiving at least one substrate, mounted inside the chamber, and —at least one system for injecting precursor gases, the system comprising an injection head including at least one nozzle for supplying the first precursor gas (41) in a main direction of axis A-A′, the at least one nozzle including: a precursor gas supply conduit (321), and an outlet member (322) generating a substantially annular 43 vortex flow (44) around axis A-A′.

A growth method of aluminum gallium nitride is disclosed. The method includes the steps of: providing a substrate; forming a first aluminum gallium nitride layer on the substrate at a first temperature; and forming a second aluminum gallium nitride layer, on the first aluminum gallium nitride layer, at a second temperature. The first temperature is higher than the second temperature.