Film-thickness measuring method, method of detecting notch portion, and polishing apparatus

Patent metadata

Field	Value
Publication number	US-2022344221-A1
Application number	US-202217694125-A
Country	US
Kind code	A1
Filing date	Mar 14, 2022
Priority date	Mar 17, 2021
Publication date	Oct 27, 2022
Grant date	—

Abstract

A polishing method capable of accurately determining a polishing end point of a substrate is disclosed. The method is a film-thickness measuring method for a substrate W using a film-thickness measuring device, at least a part of which being mounted in a polishing table configured to support the polishing pad. The method includes measuring film thicknesses of the substrate W, while rotating the substrate W on a polishing surface of the polishing pad by a polishing head and controlling a position of the film-thickness measuring device relative to the polishing head.

First claim

What is claimed is:

1 . A film-thickness measuring method for a substrate using a film-thickness measuring device, at least a part of the film-thickness measuring device being mounted to a polishing table that support a polishing pad, said method comprising:
measuring film thicknesses of the substrate, while rotating the substrate on a polishing surface of the polishing pad by a polishing head and controlling a position of the film-thickness measuring device relative to the polishing head.

2 . The film-thickness measuring method according to claim 1 , wherein controlling the position of the film-thickness measuring device relative to the polishing head comprises controlling, in synchronization with the polishing head, at least one of an oscillating motor that oscillates the polishing head along the polishing surface and a table motor that rotates the polishing table.

3 . The film-thickness measuring method according to claim 1 , wherein during the measuring of the film thicknesses of the substrate, pressures in a plurality of pressure chambers formed by an elastic membrane of the polishing head are regulated such that the polishing head presses the substrate against the polishing surface.

4 . The film-thickness measuring method according to claim 3 , wherein the pressures in the plurality of pressure chambers are regulated such that an outer portion of the substrate is pressed against the polishing surface while a central portion of the substrate is attracted.

5 . The film-thickness measuring method according to claim 1 , wherein the film-thickness measuring device is an optical film-thickness measuring device or an eddy-current-type film-thickness measuring device.

6 . The film-thickness measuring method according to claim 1 , wherein an area where the film thicknesses are measured is a periphery of the substrate.

7 . The film-thickness measuring method according to claim 6 , wherein controlling the position of the film-thickness measuring device relative to the polishing head comprises controlling the position of the film-thickness measuring device relative to the polishing head based on a rotation angle of the polishing head such that a measuring position for the film thicknesses traces a path extending in a circumferential direction of the periphery.

8 . The film-thickness measuring method according to claim 6 , wherein:
controlling the position of the film-thickness measuring device relative to the polishing head comprises controlling the position of the film-thickness measuring device relative to the polishing head such that a measuring position for the film thicknesses moves in a radial direction of the substrate in a plurality of regions arranged in a circumferential direction of the substrate; and the plurality of regions include at least the periphery of the substrate.

9 . The film-thickness measuring method according to claim 6 , wherein controlling the position of the film-thickness measuring device relative to the polishing head comprises controlling the position of the film-thickness measuring device relative to the polishing head such that a measuring position for the film thicknesses moves in a circumferential direction of the substrate while meandering in a region including at least the periphery of the substrate.

10 . A method of detecting a notch portion, comprising:
measuring film thicknesses of a periphery of a substrate by using said method according to claim 6 ; and determining a position of the notch portion of the substrate based on a measurement result of the film thicknesses.

11 . A polishing method comprising:
polishing a substrate while rotating the substrate on a polishing surface of a polishing pad by a polishing head; measuring a film thickness of the substrate by a film-thickness measuring device during the polishing of the substrate; stopping the polishing of the substrate; when a variation in film thickness of a periphery of the substrate is out of a reference range, measuring film thicknesses of the periphery of the substrate, while rotating the substrate on the polishing surface of the polishing pad by the polishing head and controlling a position of the film-thickness measuring device relative to the polishing head; and re-polishing the substrate such that the variation of the film thicknesses of the periphery of the substrate is eliminated.

12 . A polishing apparatus for polishing a substrate, comprising:
a polishing table configured to support a polishing pad; a table motor configured to rotate the polishing table; a polishing head configured to press the substrate against a polishing surface of the polishing pad; a polishing-head rotating motor configured to rotate the polishing head; a polishing-head oscillation arm coupled to the polishing head; an oscillating motor coupled to the polishing-head oscillation arm and configured to oscillate the polishing head along the polishing surface; a film-thickness measuring device configured to measure a film thickness of the substrate, at least a part of the film-thickness measuring device being mounted to the polishing table; and an operation controller configured to control an operation of the polishing apparatus, wherein the operation controller is configured to instruct the film-thickness measuring device to measure film thicknesses of the substrate, while instructing the polishing-head rotating motor to rotate the polishing head to thereby rotate the substrate and controlling a position of the film-thickness measuring device relative to the polishing head.

13 . A polishing apparatus for polishing a substrate, comprising:
a polishing table configured to support a polishing pad; a table motor configured to rotate the polishing table; a polishing head configured to press the substrate against a polishing surface of the polishing pad; a polishing-head rotating motor configured to rotate the polishing head; a polishing-head oscillation arm coupled to the polishing head; an oscillating motor coupled to the polishing-head oscillation arm and configured to oscillate the polishing head along the polishing surface; a film-thickness measuring device configured to measure a film thickness of the substrate, at least a part of the film-thickness measuring device being mounted to the polishing table; and an operation controller configured to control an operation of the polishing apparatus, wherein the operation controller is configured to:
instruct the film-thickness measuring device to measure film thicknesses of a periphery of the substrate, while instructing the polishing-head rotating motor to rotate the polishing head to thereby rotate the substrate and controlling a position of the film-thickness measuring device relative to the polishing head; and
determine a position of a notch portion based on a measurement result of the film thicknesses.

14 . The polishing apparatus according to claim 12 , wherein the operation controller is configured to control the position of the film-thickness measuring device relative to the polishing head by controlling at least one of the oscillating motor and the table motor in synchronization with the polishing head.

15 . The polishing apparatus according to claim 14 , wherein the operation controller is configured to control the position of the film-thickness measuring device relative to the polishing head based on a rotation angle of the polishing head such that a measuring position for the film thicknesses traces a path extending in a circumferential direction of a periphery of the substrate.

16 . The polishing apparatus a

Assignees

• Ebara Corp

Inventors

• Nabeya Osamu
• Togashi Shingo
• Namiki Keisuke

Classifications

• H10P72/7618

  characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating carrousel · CPC title

• H10P72/0472

  comprising at least one polishing chamber · CPC title

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• H10P74/238 Primary

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title