Polishing apparatus and polishing method

Patent metadata

Field	Value
Publication number	US-10144103-B2
Application number	US-201515118184-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 17, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

The present invention relates to a polishing apparatus and a polishing method for polishing a substrate, such as a wafer, and more particularly to a polishing apparatus and a polishing method for polishing an edge portion of a wafer with use of a polishing tape.
The polishing apparatus includes a substrate holder ( 1 ) configured to hold and rotate a substrate (W), and a polishing unit ( 7 ) configured to polish an edge portion of the substrate (W) with use of a polishing tape ( 5 ). The polishing unit ( 7 ) includes: a disk head ( 12 ) having a circumferential surface for supporting the polishing tape ( 5 ); and a head moving device ( 50 ) configured to move the disk head ( 12 ) in a tangential direction of the substrate (W) and to bring the polishing tape ( 5 ) on the circumferential surface of the disk head ( 12 ) into contact with the edge portion of the substrate (W).

First claim

The invention claimed is:

1. A polishing apparatus comprising:
a substrate holder having a substrate-holding surface configured to hold a substrate, the substrate holder being configured to rotate the substrate; and
a polishing unit configured to polish an edge portion of the substrate with use of a polishing tape,
the polishing unit including:
a disk head having a circumferential surface for supporting the polishing tape;
a head moving device configured to move the disk head in a tangential direction of the substrate and to bring the polishing tape on the circumferential surface of the disk head into contact with the edge portion of the substrate; and
a nip roller configured to press the polishing tape against the circumferential surface of the disk head to curve the polishing tape along the circumferential surface, the nip roller being adjacent to the circumferential surface of the disk head such that the polishing tape is sandwiched between the disk head and the nip roller,

wherein the disk head has its a central axis which is parallel to a surface of the substrate and is perpendicular to the tangential direction.

2. The polishing apparatus according to claim 1 , wherein the polishing unit further includes:
a first reel and a second reel holding both ends of the polishing tape; and
a first motor and a second motor configured to generate torques for rotating the first reel and the second reel in opposite directions.

3. The polishing apparatus according to claim 1 , wherein the polishing unit further includes a nip-roller moving device configured to move the nip roller around the central axis of the disk head.

4. The polishing apparatus according to claim 1 , wherein the polishing unit further includes a head motor configured to rotate the disk head about the central axis thereof.

5. The polishing apparatus according to claim 1 , wherein the polishing unit is one of a plurality of polishing units.

6. The polishing apparatus according to claim 5 , wherein the plurality of polishing units include a first polishing unit with a first polishing tape, and a second polishing unit with a second polishing tape having a polishing surface which is finer than that of the first polishing tape.

7. A polishing method comprising:
rotating a substrate about its central axis;
pressing a first polishing tape against an edge portion of the substrate by a circumferential surface of a first disk head while moving the first disk head in a tangential direction of the substrate, thereby forming a step in the edge portion; and
pressing a second polishing tape against the step by a circumferential surface of a second disk head while moving the second disk head in a tangential direction of the substrate, thereby polishing the step, the second polishing tape having a polishing surface which is finer than a polishing surface of the first polishing tape.

8. The polishing apparatus according to claim 4 , further comprising a base, the head motor being secured to the base.

9. The polishing apparatus according to claim 8 , further comprising:
a linear guide extending in parallel with the substrate-holding surface of the substrate holder, the base being movably supported by the linear guide.

10. The polishing apparatus according to claim 9 , wherein the substrate-holding surface has a circular shape, and the linear guide extends in a tangential direction of the substrate-holding surface.

11. The polishing apparatus according to claim 3 , wherein the polishing unit further includes:
a nip-roller biasing device coupled to the nip roller, the nip-roller biasing device being configured to bias the nip roller toward the central axis of the disk head; and
a pivot arm holding the nip-roller biasing device,
wherein the nip-roller moving device comprises a pivoting motor, and the pivot arm is secured to a rotational shaft of the pivoting motor.

12. The polishing apparatus according to claim 11 , wherein the polishing unit further includes a head motor configured to rotate the disk head about the central axis thereof.

13. The polishing apparatus according to claim 12 , further comprising a base, the head motor and the pivoting motor being secured to the base.

14. The polishing apparatus according to claim 13 , wherein the rotational shaft of the pivoting motor is aligned with a rotational shaft of the head motor.

15. The polishing apparatus according to claim 14 , further comprising:
a linear guide extending in parallel with the substrate-holding surface of the substrate holder, the base being movably supported by the linear guide.

16. The polishing apparatus according to claim 15 , wherein the substrate-holding surface has a circular shape, and the linear guide extends in a tangential direction of the substrate-holding surface.

Assignees

• Ebara Corp

Inventors

• Seki Masaya
• Hoshina Manao

Classifications

• H10P90/128

  by edge treatment, e.g. chamfering · CPC title

• B24B21/008

  Machines comprising two or more tools or having several working posts (B24B21/006 takes precedence) · CPC title

• B24B9/065 Primary

  of thin, brittle parts, e.g. semiconductors, wafers · CPC title

• B24B21/002 Primary

  for grinding edges or bevels · CPC title

• B24B37/04

  designed for working plane surfaces · CPC title