Method of raising polishing head after polishing of workpiece, polishing apparatus for workpiece, and computer-readable storage medium storing program

Patent metadata

Field	Value
Publication number	US-2023191553-A1
Application number	US-202218080252-A
Country	US
Kind code	A1
Filing date	Dec 13, 2022
Priority date	Dec 20, 2021
Publication date	Jun 22, 2023
Grant date	—

Abstract

A method of raising a polishing head capable of preventing a workpiece from bending and preventing an excessive stress from generating in the workpiece by avoiding contact between the workpiece and a retainer ring when the polishing head is raised from a polishing pad after polishing of the workpiece is disclosed. The method includes: polishing the workpiece by pressing the workpiece against the polishing pad while rotating the polishing head and the polishing pad; stopping the rotations of the polishing pad and the polishing head; raising the retainer ring of the polishing head relative to the workpiece to separate the retainer ring from the polishing pad and moving the retainer ring to a position higher than the workpiece; and then raising the polishing head with the workpiece held on the polishing head.

First claim

What is claimed is:

1 . A method of raising a polishing head after polishing of a workpiece, comprising:
polishing the workpiece by pressing the workpiece against a polishing pad while rotating the polishing head and the polishing pad; stopping the rotations of the polishing pad and the polishing head; raising a retainer ring of the polishing head relative to the workpiece to separate the retainer ring from the polishing pad and moving the retainer ring to a position higher than the workpiece; and then raising the polishing head with the workpiece held on the polishing head.

2 . The method according to claim 1 , further comprising holding the workpiece by the polishing head after polishing of the workpiece and before raising of the polishing head.

3 . The method according to claim 2 , wherein raising the retainer ring to the position higher than the workpiece is performed before or simultaneously with holding the workpiece by the polishing head.

4 . The method according to claim 2 , wherein holding the workpiece by the polishing head is performed while supplying fluid directly to an area between the workpiece and the polishing pad.

5 . The method according to claim 2 , wherein the polishing head includes an elastic membrane forming a plurality of pressure chambers for pressing the workpiece against the polishing pad,
holding the workpiece by the polishing head comprises holding the workpiece with the polishing head by forming a negative pressure in an outer pressure chamber of the plurality of pressure chambers and then forming a negative pressure in an inner pressure chamber of the plurality of pressure chambers.

6 . The method according to claim 2 , wherein holding the workpiece by the polishing head is performed before stopping the rotations of the polishing pad and the polishing head.

7 . The method according to claim 1 , wherein raising the polishing head comprises: raising the polishing head at a first speed until the entire workpiece is separated from the polishing pad; and raising the polishing head at a second speed higher than the first speed after the entire workpiece is separated from the polishing pad.

8 . A polishing apparatus for a workpiece, comprising:
a polishing table configured to support a polishing pad; a polishing-table rotating device configured to rotate the polishing table together with the polishing pad; a polishing head configured to press the workpiece against the polishing pad to polish the workpiece; a polishing-head pressure controller configured to control pressure in the polishing head; a polishing-head rotating device configured to rotate the polishing head; a polishing-head elevating device configured to raise and lower the polishing head relative to the polishing table; and an operation controller configured to control operations of the polishing-table rotating device, the polishing-head pressure controller, the polishing-head rotating device, and the polishing-head elevating device, the polishing head having a retainer ring surrounding the workpiece, the operation controller being configured to:
after polishing of the workpiece, instruct the polishing-table rotating device and the polishing-head rotating device to stop rotations of the polishing pad and the polishing head;
instruct the polishing-head pressure controller to raise the retainer ring relative to the workpiece to separate the retainer ring from the polishing pad and move the retainer ring to a position higher than the workpiece; and then
instruct the polishing-head elevating device to raise the polishing head with the workpiece held on the polishing head.

9 . The polishing apparatus according to claim 8 , wherein the operation controller is configured to instruct the polishing-head pressure controller to cause the polishing head to hold the workpiece after the workpiece is polished and before the polishing head is raised.

10 . The polishing apparatus according to claim 9 , wherein the operation controller is configured to instruct the polishing-head pressure controller to raise the retainer ring to the position higher than the workpiece before or simultaneously with the workpiece is held by the polishing head.

11 . The polishing apparatus according to claim 9 , further comprising a fluid supply system configured to supply fluid to an area between the workpiece and the polishing pad, the operation controller being configured to instruct the fluid supply system to supply the fluid directly to the area between the workpiece and the polishing pad when the polishing head holds the workpiece.

12 . The polishing apparatus according to claim 9 , wherein the polishing head includes an elastic membrane forming a plurality of pressure chambers for pressing the workpiece against the polishing pad, and
the operation controller is configured to instruct the polishing-head pressure controller to cause the polishing head to hold the workpiece by forming a negative pressure in an outer pressure chamber of the plurality of pressure chambers and then forming a negative pressure in an inner pressure chamber of the plurality of pressure chambers.

13 . The polishing apparatus according to claim 9 , wherein the operation controller is configured to instruct the polishing-head pressure controller to cause the polishing head to hold the workpiece before rotations of the polishing pad and the polishing head are stopped.

14 . The polishing apparatus according to claim 8 , wherein the operation controller is configured to instruct the polishing-head elevating device to raise the polishing head at a first speed until the entire workpiece is separated from the polishing pad, and raise the polishing head at a second speed higher than the first speed after the entire workpiece is separated from the polishing pad.

15 . A computer-readable storage medium storing a program for causing a computer to:
instruct a polishing-head pressure controller, a polishing-table rotating device, and a polishing-head rotating device to polish a workpiece by pressing the workpiece against a polishing pad while rotating a polishing head and the polishing pad on a polishing table; after polishing of the workpiece, instruct the polishing-table rotating device and the polishing-head rotating device to stop the rotations of the polishing pad and the polishing head; instruct the polishing-head pressure controller to raise a retainer ring of the polishing head relative to the workpiece to separate the retainer ring from the polishing pad and move the retainer ring to a position higher that the workpiece; and instruct the polishing-head elevating device to raise the polishing head with the workpiece held on the polishing head.

Assignees

• Ebara Corp

Inventors

• Kato Yuichi
• Nabeya Osamu

Classifications

• B24B37/32 Primary

  Retaining rings · CPC title

• B24B37/005 Primary

  Control means for lapping machines or devices · CPC title

• H10P72/0606

  Position monitoring, e.g. misposition detection or presence detection · CPC title

• H10P72/0428 Primary

  Apparatus for mechanical treatment or grinding or cutting · CPC title

• B24B37/30

  for single side lapping of plane surfaces · CPC title