Provided is a method for producing an n-type SiC single crystal, whereby it is possible to grow an n-type SiC single crystal having a low resistivity at a high speed. A method for producing an n-type SiC single crystal by bringing a SiC seed crystal substrate into contact with a SiC solution having such a temperature gradient that the temperature gradually decreases from the inside toward the surface, thereby achieving the crystal growth of the n-type SiC single crystal. The method involves adding a nitride to a raw material for forming the SiC solution or to the SiC solution.

A SiC single crystal comprising no polycrystals, and no cracking other than at the side edges is provided. A method for producing SiC single crystal in which seed crystal held at bottom end face of holding shaft is contacted with SiC solution having temperature gradient to grow SiC single crystal, wherein the contour of the end face of the holding shaft is smaller than the contour of the top face of the seed crystal, the top face of the seed crystal has center section held in contact with the entire surface of the end face of the holding shaft and outer peripheral section that is not in contact with the end face of the holding shaft, and carbon sheet is disposed on the top face of the seed crystal so as to cover at least the outer peripheral section, among the center section and the outer peripheral section.

A method of manufacturing an SiC single crystal includes the steps of melting a raw material in a crucible (14) to produce an SIC solution (15); and bringing a crystal growth surface (24A) of an SiC seed crystal (24) into contact with the SiC solution to cause an SiC single crystal to grow on the crystal growth surface. The crystal structure of the SiC seed crystal is the 4H polytype. The off-angle of the crystal growth surface is not smaller than 1 and not larger than 4. The temperature of the SIC solution during growth of the SiC single crystal is not lower than 1650 C. and not higher than 1850 C. The temperature gradient in a portion of the SiC solution directly below the SiC seed crystal during growth of the SiC single crystal is higher than 0 C./cm and not higher than 19 C./cm.

A crystal preparation apparatus (100) and a crystal preparation method (700). The crystal preparation apparatus (100) comprises: a growth cavity (110), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); and a heating assembly (120), used for heating the growth cavity (110). The crystal preparation method (700) comprises: placing a raw material in the growth cavity (110) (710), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); heating the growth cavity (110) by means of the heating assembly (120) so as to melt the raw material into a melt (720); bonding a seed crystal (180) to a seed crystal holder (150) (730); lowering the seed crystal holder (150) to which the seed crystal (180) is bonded, so that the seed crystal (180) is in contact with the melt; and preparing a crystal on the basis of the seed crystal (180) and the melt (750).

The production method of an SiC single crystal is a production method of an SiC single crystal by a solution growth process. The production method includes a contact step A, a contact step B, and a growth step. In the contact step A, a partial region of the principal surface is brought into contact with a stored SiC solution. In the contact step B, a contact region between the principal surface and the stored SiC solution expands, due to a wetting phenomenon, starting from an initial contact region which is the partial region brought into contact in the contact step A. In the growth step, an SiC single crystal is grown on the principal surface which is in contact with the stored SiC solution.

A p-type SiC single crystal having lower resistivity than the prior art is provided. This is achieved by a method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the surface, to grow a SiC single crystal, the method comprising: using as the SiC solution a SiC solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al; and contacting a (0001) face of the SiC seed crystal substrate with the SiC solution to grow a SiC single crystal from the (0001) face.

At least two types of dielectric materials such as oxide nanosheets having a layered perovskite structure that differ from each other are laminated, and the nanosheets are bonded to each other via an ionic material, thereby producing a superlattice structure-having ferroelectric thin film. Having the layered structure, the film can exhibit ferroelectricity as a whole, though not using a ferroelectric material therein. Accordingly, there is provided a ferroelectric film based on a novel principle, which is favorable for ferroelectric memories and others and which is free from a size effect even though extremely thinned.

A method of growing a group III nitride single crystal, including steps of forming a plurality of initial nuclei on a seed substrate having seed crystals made of a group III nitride single crystal formed thereon by immersing the substrate into a mixed melt in a crucible; forming a planarized crystal surface by immersing into a mixed melt in a crucible and pulling up therefrom to heat the substrate; and forming a thickened group III nitride single crystal on the seed substrate. When forming the plurality of initial nuclei, a concentration of alkali metals or alkaline earth metals other than Na in the mixed melt is set to 0.001 mol % or less, and when forming the thickened group III nitride single crystal, a concentration of alkali metals or alkaline earth metals other than Na in the mixed melt is set higher than that when forming the plurality of initial nuclei.