In SiC single crystal production by the solution process, an alloy of silicon (Si) and a metallic element M that increases the solubility of carbon (C) is pre-impregnated into a SiC sintered body having a relative density of 50 to 90%, following which Si and M are placed in a SiC crucible made of the SiC sintered body and the Si and M within the SiC crucible are melted, forming a Si—C solution. With heating, SiC from the SiC sintered body dissolves into the Si—C solution, efficiently supplying Si and C to the Si—C solution. As a result, Si and C are supplied uniformly and in the proper amount from all areas of contact between the SiC crucible and the Si—C solution, enabling a high-quality SiC single crystal to be stably produced over a long time at a rapid growth rate.

In SiC single crystal production by the solution process, an alloy of silicon (Si) and a metallic element M that increases the solubility of carbon (C) is pre-impregnated into a SiC sintered body having a relative density of 50 to 90%, following which Si and M are placed in a SiC crucible made of the SiC sintered body and the Si and M within the SiC crucible are melted, forming a Si—C solution. With heating, SiC from the SiC sintered body dissolves into the Si—C solution, efficiently supplying Si and C to the Si—C solution. As a result, Si and C are supplied uniformly and in the proper amount from all areas of contact between the SiC crucible and the Si—C solution, enabling a high-quality SiC single crystal to be stably produced over a long time at a rapid growth rate.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron in the center of the epitaxial layer is less than 5.0×10.sup.12 cm.sup.−3.

A member for an apparatus for manufacturing a semiconductor single crystal having long product life and a tantalum carbide coated carbon material are provided. The tantalum carbide coated carbon material according to the present invention is a tantalum carbide coated carbon material in which at least a part of a surface of a carbon base material is coated with a tantalum carbide coated film containing tantalum carbide as a main component, in which in the tantalum carbide coated film, an intensity of an X-ray diffraction line corresponding to a plane with respect to an out-of-plane direction is larger than intensities of X-ray diffraction lines corresponding to other crystal planes, and the intensity ratio is 60% or more with respect to a sum of intensities of X-ray diffraction lines corresponding to all crystal planes.

A member for an apparatus for manufacturing a semiconductor single crystal having long product life and a tantalum carbide coated carbon material are provided. The tantalum carbide coated carbon material according to the present invention is a tantalum carbide coated carbon material in which at least a part of a surface of a carbon base material is coated with a tantalum carbide coated film containing tantalum carbide as a main component, in which in the tantalum carbide coated film, an intensity of an X-ray diffraction line corresponding to a plane with respect to an out-of-plane direction is larger than intensities of X-ray diffraction lines corresponding to other crystal planes, and the intensity ratio is 60% or more with respect to a sum of intensities of X-ray diffraction lines corresponding to all crystal planes.

In an embodiment, a system includes a three-dimensional (3D) printer, a neutral feedstock, a p-doped feedstock, an n-doped feedstock, and a laser. The 3D printer includes a platen and an enclosure. The platen includes an inert metal. The enclosure includes an inert atmosphere. The neutral feedstock is configured to be deposited onto the platen. The neutral feedstock includes a halogenated solution and a nanoparticle having a negative electron affinity. The p-doped feedstock is configured to be deposited onto the platen. The p-doped feedstock includes a boronated compound introduced to the neutral feedstock. The n-doped feedstock is configured to be deposited onto the platen. The n-doped feedstock includes a phosphorous compound introduced to the neutral feedstock. The laser is configured to induce the nanoparticle to emit solvated electrons into the halogenated solution to form, by reduction, layers of a ceramic comprising a neutral layer, a p-doped layer, and an n-doped layer.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron is less than 1.0×10.sup.14 cm.sup.−3 at any position in the plane of the epitaxial layer.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron is less than 1.0×10.sup.14 cm.sup.−3 at any position in the plane of the epitaxial layer.

A control device has a learning model that outputs an estimated value of a second physical quantity that is unobservable under a condition of manufacturing a SiC crystal, from a first physical quantity that is observable under the condition of manufacturing the SiC crystal. The control device generates a basic learning model by mechanical learning using, as teacher data, a simulation result of a simulation model based on structural data of a SiC crystal manufacturing apparatus. The control device acquires measured values of the first physical quantity and the second physical quantity measured under a condition that the SiC crystal is unable to be manufactured while the second physical quantity is observable, and generates the learning model that corrects an output of the basic learning model based on the measured values.

A control device has a learning model that outputs an estimated value of a second physical quantity that is unobservable under a condition of manufacturing a SiC crystal, from a first physical quantity that is observable under the condition of manufacturing the SiC crystal. The control device generates a basic learning model by mechanical learning using, as teacher data, a simulation result of a simulation model based on structural data of a SiC crystal manufacturing apparatus. The control device acquires measured values of the first physical quantity and the second physical quantity measured under a condition that the SiC crystal is unable to be manufactured while the second physical quantity is observable, and generates the learning model that corrects an output of the basic learning model based on the measured values.