A method comprises transporting a first stream of a carrier gas to a delivery device that contains a liquid precursor compound. The method further comprises transporting a second stream of the carrier gas to a point downstream of the delivery device. The first stream after emanating from the delivery device and the second stream are combined to form a third stream, such that the dew point of the vapor of the liquid precursor compound in the third stream is lower than the temperature of the plumbing that transports the vapor to a CVD reactor or a plurality of CVD reactors. The flow direction of the first stream, the flow direction of the second stream and the flow direction of the third stream are unidirectional and are not opposed to each other.

A composition (or an aggregate) comprising an epitaxial h-BN/BNNT structure that comprises a hexagonal boron nitride structure that is epitaxial with respect to a boron nitride nanotube structure. Also, a composition (or an aggregate) that comprises independent boron nitride nanotubes, in which a total mass percentage of independent hexagonal boron nitride and residual boron in the composition is not more than 35%. Also, a composition (or an aggregate) in which not more than 1% of independent boron nitride nanotubes and boron nitride nanotube structures have a dixie cup or bamboo defect. Also, a composition in which at least 50% of independent boron nitride nanotubes and boron nitride nanotube structures are single-wall. Also, a method of making a composition that comprises epitaxial h-BN/BNNT structures.

There is provided a nitride crystal substrate having a main surface and formed of group-III nitride crystal, wherein N.sub.IR/N.sub.Elec, satisfies formula (1) below, which is a ratio of a carrier concentration N.sub.IR at a center of the main surface relative to a carrier concentration N.sub.Elec: 0.5≤N.sub.IR/N.sub.Elec≤1.5 . . . (1) where N.sub.IR is the carrier concentration on the main surface side of the nitride crystal substrate obtained based on a reflectance of the main surface measured by a reflection type Fourier transform infrared spectroscopy, and N.sub.Elec is the carrier concentration in the nitride crystal substrate obtained based on a specific resistance of the nitride crystal substrate and a mobility of the nitride crystal substrate measured by an eddy current method.

A SiC epitaxial wafer of the present invention includes a SiC single crystal substrate, and a high concentration layer that is provided on the SiC single crystal substrate and has an average value of an n-type doping concentration of 1×10.sup.18/cm.sup.3 or more and 1×10.sup.19/cm.sup.3 or less, and in-plane uniformity of the doping concentration of 30% or less.

A method for producing a gallium oxide semiconductor film by a mist CVD method, including, a mist-forming step in which a raw material solution containing gallium is misted in a mist-forming unit to generate mist, a carrier gas supply step of supplying a carrier gas for transferring the mist to the mist-forming unit, a transferring step of transferring the mist from the mist-forming unit to a film forming chamber using the carrier gas via a supply pipe connecting the mist-forming unit and the film forming chamber, a rectification step of rectifying flow of the mist and the carrier gas supplied to a surface of a substrate in the film forming chamber so as to flow along the surface of the substrate, a film forming step of heat-treating the rectified mist to form a film on the substrate, and an exhaust step of exhausting waste gas upward from the substrate.

A method for manufacturing diamond substrate of using source gas containing hydrocarbon gas and hydrogen gas to form diamond crystal on an underlying substrate by CVD method, to form a diamond crystal layer having nitrogen-vacancy centers in at least part of the diamond crystal, nitrogen or nitride gas is mixed in the source gas, wherein the source gas is: 0.005 volume % or more and 6.000 volume % or less of the hydrocarbon gas; 93.500 volume % or more and less than 99.995 volume % of the hydrogen gas; and 5.0×10.sup.−5 volume % or more and 5.0×10.sup.−1 volume % or less of the nitrogen gas or the nitride gas, and the diamond crystal layer having the nitrogen-vacancy centers is formed. A method for manufacturing a diamond substrate to form an underlying substrate, a diamond crystal having a dense nitrogen-vacancy centers (NVCs) with an orientation of NV axis by performing the CVD.

Embodiments provide a way of treating source/drain recesses with a high heat treatment and an optional hydrogen plasma treatment. The high heat treatment smooths the surfaces inside the recesses and remove oxides and etching byproducts. The hydrogen plasma treatment enlarges the recesses vertically and horizontally and inhibits further oxidation of the surfaces in the recesses.

A method for preparing suspended graphene support film by selectively etching growth substrate is disclosed in present invention. The transfer process of graphene is avoided. The process of present invention is efficient and low in cost, suspended graphene support film can be prepared in a single etching step. The prepared graphene support film does not need any support by polymer film and polymer fiber. The prepared graphene support film has controllable number of layers and high intactness (90%-97%), large suspended area (diameter is 10-50 μm), wide clean area (>100 nm) and can be mass-produced. In addition, the graphene support film can be directly used as transmission electron microscope support film, and can be used to achieve high resolution imaging of nanoparticles.

Aspects of the present disclosure generally relate to oscillating a boundary layer of a flow of process gas in methods and systems for processing substrates. In one aspect, one or more of a pressure, a gas flow rate, and/or a height of a substrate are oscillated during processing. In one implementation, a method of processing a substrate includes conducting a processing operation on the substrate in an interior volume of a processing chamber. The conducting the processing operation on the substrate includes moving a flow of one or more process gases over a surface of the substrate. The method also includes oscillating a boundary layer of the flow of one or more process gases while the flow of one or more process gases moves over the surface of the substrate.

An apparatus for producing a Group-III nitride semiconductor crystal includes a raw material reaction chamber, a raw material reactor which is provided in the raw material reaction chamber and configured to generate a Group-III element-containing gas, a board-holding member configured to hold a board in the raw material reaction chamber, a raw material nozzle configured to spray the Group-III element-containing gas toward the board, a nitrogen source nozzle configured to spray a nitrogen element-containing gas toward the board, in which, in a side view seen in a direction perpendicular to a vertical direction, a spray direction of the nitrogen source nozzle intersects with a spray direction of the raw material nozzle before the board, and a mixing part in which the Group-III element-containing gas and the nitrogen element-containing gas are mixed together is formed around the intersection as a center, a heater, and a rotation mechanism.