According to one embodiment, a treatment method may include making a byproduct come into contact with a treatment solution, wherein the byproduct is a solid or liquid byproduct formed by polymerizing components contained in an exhaust gas discharged by synthesizing a silicon-containing material using a gas which includes silicon and halogen. The treatment solution may include at least one of an inorganic base or an organic base, and is basic.

A method for producing a group 13 nitride single crystal includes dissolving and crystal growing. The dissolving includes dissolving nitrogen in a mixed melt in a reaction vessel that contains the mixed melt, a seed crystal, and a surrounding member. The mixed melt contains an alkali metal and a group 13 metal. The seed crystal is a seed crystal that is placed in the mixed melt and includes a group 13 nitride crystal in which a principal face is a c-plane. The surrounding member is arranged so as to surround the entire area of a side face of the seed crystal. The crystal growing includes growing a group 13 nitride crystal on the seed crystal.

Provided is a method for producing a SiC single crystal which can suppress generation of SiC polycrystals. The method according to the present embodiment is in accordance with a solution growth method. The method for producing a SiC single crystal according to the present embodiment comprises a power-output increasing step, a contact step, and a growth step. In the power-output increasing step, high-frequency power output of an induction heating device is increased to crystal-growth high-frequency power output. In the contact step, a SiC seed crystal is brought into contact with a SiC solution. The high-frequency power output of the induction heating device in the contact step is more than 80% of the crystal-growth high-frequency power output. The temperature of the SiC solution in the contact step is less than a crystal growth temperature. In the growth step, the SiC single crystal is grown at the crystal growth temperature.

Provided is a method for producing a SiC single crystal which can suppress generation of SiC polycrystals. The method according to the present embodiment is in accordance with a solution growth method. The method for producing a SiC single crystal according to the present embodiment comprises a power-output increasing step, a contact step, and a growth step. In the power-output increasing step, high-frequency power output of an induction heating device is increased to crystal-growth high-frequency power output. In the contact step, a SiC seed crystal is brought into contact with a SiC solution. The high-frequency power output of the induction heating device in the contact step is more than 80% of the crystal-growth high-frequency power output. The temperature of the SiC solution in the contact step is less than a crystal growth temperature. In the growth step, the SiC single crystal is grown at the crystal growth temperature.

A production method according an embodiment of the present invention is to produce a SiC single crystal by a solution growth technique, and includes a formation step and a growth step. In the formation step, material of SiC solution contained in a crucible is melted, and a SiC solution is formed. In the growth step, a SiC seed crystal attached to a bottom end of a seed shaft is brought into contact with the SiC solution, and a SiC single crystal is grown on a crystal growth surface of the SiC seed crystal. In the growth step, while a temperature of the SiC solution is being raised, the SiC single crystal is grown. The SiC single crystal production method according to the embodiment facilitates production of a SiC single crystal of a desired polytype.

A production method according an embodiment of the present invention is to produce a SiC single crystal by a solution growth technique, and includes a formation step and a growth step. In the formation step, material of SiC solution contained in a crucible is melted, and a SiC solution is formed. In the growth step, a SiC seed crystal attached to a bottom end of a seed shaft is brought into contact with the SiC solution, and a SiC single crystal is grown on a crystal growth surface of the SiC seed crystal. In the growth step, while a temperature of the SiC solution is being raised, the SiC single crystal is grown. The SiC single crystal production method according to the embodiment facilitates production of a SiC single crystal of a desired polytype.

A method for producing a SiC single crystal with few dislocations and defects and a large diameter enlargement ratio is provided. A method for producing a SiC single crystal by solution process, wherein a bottom face of a seed crystal is (0001) or (000-1) face and has circular shape with at least a partially removed section and a circular arc-shaped section on an outer periphery, the number of the removed sections is one or more, shapes of the removed sections are bow-shaped with a minor arc or semi-circumference removed along a chord connecting two points on the circular arc, a central angle formed by a center of the circular shape and the two points is 40 or greater, and a total of the central angles of the removed sections is no greater than 180, the method comprising forming a meniscus and growing the single crystal from the bottom face.

A method for producing a SiC single crystal with few dislocations and defects and a large diameter enlargement ratio is provided. A method for producing a SiC single crystal by solution process, wherein a bottom face of a seed crystal is (0001) or (000-1) face and has circular shape with at least a partially removed section and a circular arc-shaped section on an outer periphery, the number of the removed sections is one or more, shapes of the removed sections are bow-shaped with a minor arc or semi-circumference removed along a chord connecting two points on the circular arc, a central angle formed by a center of the circular shape and the two points is 40 or greater, and a total of the central angles of the removed sections is no greater than 180, the method comprising forming a meniscus and growing the single crystal from the bottom face.

A single-crystal silicon carbide wafer (31) of the present invention includes boron at a concentration of 1.010.sup.16 atoms/cm.sup.3 or less, and has a central region (33) whose basal plane dislocation density is 100/cm.sup.2 or less on the surface. The central region (33) includes the center of the surface of the single-crystal silicon carbide wafer (31). An area of the central region (33) is one fourth or more of an area of the surface of the single-crystal silicon carbide wafer (31).

A non-enzymatic glucose biosensor and a manufacturing method thereof and a manufacturing method of a nanometal catalyst are provided. The non-enzymatic glucose biosensor includes a voltage source and a working electrode. The working electrode is electrically connected to the voltage source, wherein the working electrode includes a substrate and a nanometal catalyst. The nanometal catalyst is deposited on the substrate and includes polygonal block nanostructures, wherein the nanometal catalyst catalyzes the oxidation reaction of glucose.