A method of producing a silicon carbide single crystal capable of producing a silicon carbide single crystal substrate in which the number of occurrences of basal plane dislocations is reduced to 100 cm.sup.2 or less is provided. The method of producing a silicon carbide single crystal includes in this order: a preliminary heating step of heating a silicon carbide seed crystal to a temperature of 2000 C. or higher, before growing the silicon carbide single crystal on the silicon carbide seed crystal, in the state in which the silicon carbide seed crystal is attached on an arranged graphite member on one side of a crucible, and a silicon carbide raw material is provided on the other side; and a cooling step of cooling the silicon carbide seed crystal to a room temperature.

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.

A method and a system for film deposition, the system comprising a substrate and a negatively biased target, the target being mounted on a magnetron sputtering cathode and located at a distance from the substrate, wherein a laser beam from a pulsed laser is focused on the target, thereby triggering a magnetron plasma or ejecting vaporized and ionized material from the target in an existing magnetron plasma, the magnetron plasma sputtering material from the target depositing on the substrate.

In a state in which a SiC container (3) of a material including polycrystalline SiC is housed in a TaC container (2) of a material including TaC and in which an underlying substrate (40) is housed in the SiC container (3), the TaC container (2) is heated in an environment where a temperature gradient occurs in such a manner that inside of the TaC container (2) is at a Si vapor pressure. Consequently, C atoms sublimated by etching of the inner surface of the SiC container (3) are bonded to Si atoms in an atmosphere so that an epitaxial layer (41) of single crystalline 3C-SiC thereby grows on the underlying substrate (40).

A method includes a graphene precursor formation process of: heating a SiC substrate to sublimate Si atoms in a Si surface of the SiC substrate so that a graphene precursor is formed; and stopping the heating before the graphene precursor is covered with graphene. A SiC substrate to be treated in the graphene precursor formation process is provided with a step including a plurality of molecular layers. The step has a stepped structure in which a molecular layer whose C atom has two dangling bonds is disposed closer to the surface than a molecular layer whose C atom has one dangling bond.

A cobalt ferrite film consisting of twinned cobalt ferrite isomer crystals, metastable normal Co.sup.2+.sub.tet[Fe.sup.3+.sub.oct].sub.2O.sub.4 isomer [nCFO] and tetragonal inverted Fe.sup.3+.sub.tet[Co.sup.2+Fe.sup.3+].sub.octO.sup.4 isomer [iCFO], the nCFO and iCFO isomer crystals alternating in chessboard fashion in three dimensions, the cobalt ferrite film made by pulsed laser deposition in a vacuum chamber from a polycrystalline CoFe.sub.2O.sub.4 target on a single crystal one-side polished MgO substrate preferably heated to a temperature of greater than about 600? C.

A silicon carbide substrate includes a dopant. The silicon carbide substrate has, on an off-downstream side with respect to a center of the silicon carbide substrate in plan view, a portion having a resistivity lower than a resistivity at the center of the silicon carbide substrate in plan view. A value obtained by dividing a difference between the resistivity of the silicon carbide substrate at the center of the silicon carbide substrate in plan view and a minimum resistivity of the silicon carbide substrate on the off-downstream side with respect to the center of the silicon carbide substrate in plan view by the resistivity of the silicon carbide substrate at the center of the silicon carbide substrate in plan view is 0.015 or less. The resistivity of the silicon carbide substrate increases from a position at which the silicon carbide substrate has the minimum resistivity toward the off-downstream side.

Provided is a SiC single crystal wafer, which is manufactured from a SiC single crystal ingot grown by the sublimation-recrystallization method, and which brings about high device performance and high device manufacture yield when used as a wafer for manufacturing a device. The SiC single crystal wafer has, in a surface thereof, a basal plane dislocation density of 1,000 dislocations per cm.sup.2 or less, a threading screw dislocation density of 500 dislocations per cm.sup.2 or less, and a Raman index of 0.2 or less. Further provided is a method of manufacturing a SiC single crystal ingot, including controlling heat input from a side surface of the single crystal ingot during growth of a single crystal, to thereby grow the crystal while changes in the temperature distribution of the single crystal ingot are reduced.

A terahertz antenna includes at least one photoconductive layer which generates charge carriers upon irradiation of light and two electroconductive antenna elements via which an electric field can be applied to at least one section of the photoconductive layer. The photoconductive layer being doped with a dopant in a concentration of at least 11018 cm3, the dopant being a transition metal. The photoconductive layer is produced by molecular beam epitaxy at a growth temperature of at least 200 C. and not more than 500 C., the dopant being arranged in the photoconductive layer such that it produces a plurality of point defects.

Silicon carbide (SiC) wafers and related methods are disclosed that include large diameter SiC wafers with wafer shape characteristics suitable for semiconductor manufacturing. Large diameter SiC wafers are disclosed that have reduced deformation related to stress and strain effects associated with forming such SiC wafers. As described herein, wafer shape and flatness characteristics may be improved by reducing crystallographic stress profiles during growth of SiC crystal boules or ingots. Wafer shape and flatness characteristics may also be improved after individual SiC wafers have been separated from corresponding SiC crystal boules. In this regard, SiC wafers and related methods are disclosed that include large diameter SiC wafers with suitable crystal quality and wafer shape characteristics including low values for wafer bow, warp, and thickness variation.