Silicon carbide single crystal and method and apparatus for producing the same

Abstract

A method of producing a silicon carbide single crystal in which a sublimation raw material 40 is accommodated at the side of vessel body 12 in a graphite crucible 10, placing a seed crystal of a silicon carbide single crystal at the side of cover body 11 of the graphite crucible 10, the sublimation raw material 40 is sublimated by a first induction heating coil 21 placed at the side of sublimation raw material 40, a re-crystallization atmosphere is form by a second induction heating coil 20 placed at the side of cover body 11 so that the sublimation raw material 40 sublimated by the first induction heating coil 21 is re-crystallizable only in the vicinity of the seed crystal of a silicon carbide single crystal, and the sublimation raw material 40 is re-crystallized on the seed crystal of a silicon carbide single crystal, and a silicon carbide single crystal 60 is grown while keeping the whole surface of its growth surface in convex shape through the all growth processes. A high quality silicon carbide single crystal with large diameter excellent in dielectric breakdown property, heat resistance, radiation resistance and the like, suitable for electronic and optical devices and the like, and showing no contamination of polycrystals and polymorphs, no defect of micropipes and the like can be produced efficiently without cracking and the like.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a silicon carbide single crystal particularly suitable as an electronic device, optical device or the like, and a method and an apparatus which can produce this silicon carbide single crystal efficiently. [0003] 2. Description of the Related Art [0004] Silicon carbide shows a larger band gap and is excellent in dielectric breakdown property, heat resistance, radiation resistance and the like as compared with silicon. Therefore, silicon carbide has been noticed as an electronic device material for small-size high output semiconductors and the like, or as an optical device material owing to its excellent optical property. Of such silicon carbide crystals, silicon carbide single crystals have a merit that, when applied to devices such as a wafer and the like, uniformity of properties in a wafer is particularly excellent as compared with a silicon carbide polycrystals. [0005] Though ther...

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Benefits of technology

[0010] An object of the present invention is to provide a high quality silicon carbide single crystal excellent in dielectric breakdown property, heat resistance, radiation resistance and the like, particularly suitable for electronic devices such as semiconductor wafers and the like and optical devices such as emitting diodes and the like, and having no contamination of polycrystals and polymorphs and no defects such as micropipes and the like, and a method and an apparatus which can efficiently and easily produce the above-mentioned high quality silicon carbide single crystal with large diameter, under condition including no breakages such as cracking and the like.

[0104] The silicon carbide single crystal described in <27> is produced by the method of producing a silicon carbide single crystal described in any of <1> to <26>. Therefore, the resulting silicon carbide single crystal shows no breakages such as cracking and the like and has no crystal defects such as contamination of polycrystals and polymorphs and micropipes and the like present, namely, has extremely high quality and excellent in dielectric breakdown property, heat resistance, radiation resistance and the like and suitable particularly for electronic devices such as semiconductor wafers and the like, optical devices such as light emitting diodes and the like.

Problems solved by technology

Though there are some conventionally suggested methods of producing the above-mentioned silicon carbide single crystal, each of them have a problem that the resulting silicon carbide single crystal shows contamination of a polycrystal or polymorphs and crystal defects in the form of hollow pipe (so-called, micropipe).

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