Sic epitaxial wafer and method for producing same, and device for producing sic epitaxial wafer

Abstract

A SiC epitaxial wafer manufacturing method of the present invention includes: manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a surface of a SiC single crystal wafer while supplying a raw material gas into a chamber using a SIC epitaxial wafer manufacturing apparatus; and manufacturing a subsequent SiC epitaxial wafer after measuring a surface density of triangular defects originating from a material piece of an internal member of the chamber on the SiC epitaxial layer of the previously manufactured SiC epitaxial wafer.

Description

TECHNICAL FIELD[0001]The present invention relates to a SiC epitaxial wafer, a SiC epitaxial wafer manufacturing method, and a SiC epitaxial wafer manufacturing apparatus.[0002]Priority is claimed on Japanese Patent Application No. 2011-157918, filed Jul. 19, 2011, the content of which is incorporated herein by reference.BACKGROUND ART[0003]Silicon carbide (SiC) has characteristics in which a breakdown electric field is larger by a single digit, a band gap is three times larger, and thermal conductivity is about three times larger than silicon (Si). Accordingly, silicon carbide (SiC) is expected to be applied to power devices, high-frequency devices, high-temperature operation devices, and the like. A SiC epitaxial wafer is manufactured by growing a SiC epitaxial layer serving as an active region of a SiC semiconductor device on a SiC single crystal wafer processed from bulk single crystal of SiC produced by a sublimation method or the like according to chemical vapor deposition (CV...

AI Technical Summary

Benefits of technology

The present invention relates to a method and apparatus for manufacturing a SiC epitaxial wafer with reduced triangular defects. The method includes measuring the surface density of triangular defects on the SiC epitaxial layer of a previously manufactured SiC epitaxial wafer, and replacing the wafer if the surface density exceeds a predetermined level. The apparatus includes a shielding plate and a top plate, with the shielding plate close to the lower surface of the top plate to prevent deposits and collect dust. The use of the shielding plate reduces the amount of material pieces falling from the shielding plate to the wafer, resulting in a larger number of devices that can be obtained from a single SiC epitaxial wafer. The method and apparatus also allow for the manufacture of a SiC epitaxial wafer with reduced triangular defects, improving the yield of devices.

Problems solved by technology

In addition to the foregoing triangular defect, a minute broken piece (hereinafter referred to as a “downfall”) of a SiC film falling on a SiC single crystal wafer or a SiC epitaxial layer is also a cause of deterioration in the quality of the SiC epitaxial layer.

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