Surface machining method for single crystal SiC substrate, manufacturing method thereof, and grinding plate for surface machining single crystal SiC substrate

• US 9,960,048 B2
• Filed: 03/02/2017
• Issued: 05/01/2018
• Est. Priority Date: 02/13/2013
• Status: Active Grant

• Current Assignee: Resonac Corp. (Resonac Holdings Corp.)
• Original Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Inventors: Kido, Takanori, Kato, Tomohisa
• Primary Examiner(s): Carlson, Marc
• Application Number:
  US15/448,462
• Publication Number:
  US 20170178919A1
• Time in Patent Office: 425 Days
• CPC Class Codes: B24B 37/245 Pads with fixed abrasives
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: C30B 33/00 After-treatment of single crystals or homogeneous polycrystalline material with defined structure C30B31/00 takes precedence
• CPC Class Codes: H01L 21/02013 Grinding, lapping
• CPC Class Codes: H01L 21/02024 Mirror polishing
• CPC Class Codes: H01L 21/30625 With simultaneous mechanical treatment, e.g. mechanico-chemical polishing
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 29/1608 Silicon carbide

Abstract

A surface machining method for a single crystal SiC substrate, including: a step of mounting a grinding plate which includes a soft pad and a hard pad sequentially attached onto a base metal having a flat surface, a step of generating an oxidation product by using the grinding plate, and a step of grinding the surface while removing the oxidation product, wherein abrasive grains made of at least one metallic oxide that is softer than single crystal SiC and has a bandgap are fixed to the surface of the hard pad.

Claims

1. A grinding plate for surface machining a single crystal SiC substrate including a soft pad and a hard pad sequentially attached onto a base metal having a flat surface,

wherein abrasive grains made of at least one metallic oxide that is softer than single crystal SiC and has a bandgap are fixed to the surface of the hard pad, and

wherein the hard pad is segmented.

2. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the metal oxide is one or more selected from cerium oxide, titanium oxide, silicon oxide, aluminum oxide, iron oxide, zirconium oxide, zinc oxide, and tin oxide.

3. The grinding plate for surface machining a single crystal SiC substrate according to claim 2,

wherein the metal oxide includes at least cerium oxide.

4. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the specific surface area of the abrasive grains is in a range of 0.1 m²/g to 300 m²/g.

5. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the soft pad is a non-woven fabric or suede-based pad.

6. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the hard pad is a foamed polyurethane-based pad.

7. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the abrasive grains are fixed by using a binding agent and/or an adhesive.

8. The grinding plate for surface machining a single crystal SiC substrate according to claim 1,

wherein the abrasive grains are fixed by attaching an abrasive grain-fixed film to the hard pad.

9. A grinder for surface machining a single crystal SiC substrate, which comprises:

a grinding plate mounted in the grinder, wherein the grinding plate comprises a soft pad and a hard pad sequentially attached onto a base metal having a flat surface; and

abrasive grains made of at least one metallic oxide that is softer than single crystal SiC and has a bandgap are fixed to the surface of the hard pad,

a table for a substance to be machined to which a single crystal SiC substrate is fixed, and

a rotating unit, by which the abrasive grains of the grinding plate is contacted with a surface to be machined of a substance to be machined, while the grinding plate is rotated together with the table, and

wherein the hard pad is segmented.