Polishing head system and polishing apparatus

Patent metadata

Field	Value
Publication number	US-2021237224-A1
Application number	US-202117147677-A
Country	US
Kind code	A1
Filing date	Jan 13, 2021
Priority date	Jan 17, 2020
Publication date	Aug 5, 2021
Grant date	—

Abstract

A polishing head system capable of precisely controlling a film-thickness profile of a workpiece, such as a wafer, substrate, or panel, is disclosed. The polishing head system includes a polishing head having a plurality of piezoelectric elements configured to apply pressing forces to a workpiece, and an operation controller configured to determine instruction values of voltages to be applied to the plurality of piezoelectric elements.

First claim

What is claimed is:

1 . A polishing head system for polishing a workpiece by pressing the workpiece against a polishing surface while moving the workpiece and the polishing surface relative to each other in a presence of a polishing liquid, comprising:
a polishing head having a plurality of actuators configured to apply pressing forces to a plurality of regions of the workpiece; a drive source configured to operate the plurality of actuators; and an operation controller configured to determine a plurality of instruction values and transmits the plurality of instruction values to the drive source.

2 . The polishing head system according to claim 1 , wherein:
the plurality of actuators comprise a plurality of piezoelectric elements; the drive source comprises a drive-voltage application device including a power supply unit and a voltage controller; the power supply unit is configured to apply voltages to the plurality of piezoelectric elements independently; and the operation controller is configured to determine a plurality of instruction values of the voltages to be applied to the plurality of piezoelectric elements.

3 . The polishing head system according to claim 2 , wherein the plurality of piezoelectric elements are arranged along a radial direction and a circumferential direction of the polishing head.

4 . The polishing head system according to claim 3 , wherein an arrangement of the plurality of piezoelectric elements in the polishing head is any one or a combination of a grid arrangement, a concentric arrangement, and a staggered arrangement.

5 . The polishing head system according to claim 2 , wherein:
the polishing head further includes a plurality of pressing members coupled to the plurality of piezoelectric elements, respectively; and the plurality of pressing members has a plurality of first surfaces facing the plurality of piezoelectric elements, respectively, and a plurality of second surfaces for pressing the workpiece.

6 . The polishing head system according to claim 5 , wherein the plurality of second surfaces have at least one of a circular shape, an ellipse shape, a polygonal shape, and an arc shape.

7 . The polishing head system according to claim 5 , wherein a facing area of the plurality of first surfaces is larger than a facing area of the plurality of second surfaces.

8 . The polishing head system according to claim 5 , wherein at least two piezoelectric elements are coupled to one pressing member.

9 . The polishing head system according to claim 5 , wherein the polishing head further includes a holding member holding the plurality of pressing members such that the plurality of pressing members are movable within a limited range.

10 . The polishing head system according to claim 9 , wherein the holding member is configured to limit a range of movement of the plurality of pressing members in a direction perpendicular to a direction of pressing the workpiece.

11 . The polishing head system according to claim 5 , wherein:
the plurality of pressing members include a plurality of gimbal mechanisms, respectively, the plurality of gimbal mechanisms having a plurality of movable members which are tiltable in all directions; and the plurality of movable members have the plurality of second surfaces, respectively.

12 . The polishing head system according to claim 2 , wherein the polishing head further includes an elastic membrane having a contact surface with the workpiece.

13 . The polishing head system according to claim 5 , further comprising:
an elastic membrane forming a pressure chamber in the polishing head; and a compressed-gas supply line communicating with the pressure chamber, the pressure chamber being located between the plurality of pressing members and the elastic membrane.

14 . The polishing head system according to claim 5 , further comprising:
an elastic sheet forming a pressure chamber in the polishing head; and a compressed-gas supply line communicating with the pressure chamber, the plurality of piezoelectric elements being located between the elastic sheet and the plurality of pressing members.

15 . The polishing head system according to claim 5 , wherein the polishing head further includes a plurality of pressing-force measuring devices configured to measure pressing forces generated by the plurality of piezoelectric elements, respectively.

16 . The polishing head system according to claim 15 , wherein the plurality of pressing-force measuring devices are arranged between the plurality of piezoelectric elements and the plurality of pressing members.

17 . The polishing head system according to claim 15 , wherein the plurality of pressing-force measuring devices are a plurality of piezoelectric sensors.

18 . The polishing head system according to claim 2 , wherein the polishing head further includes a voltage distributor electrically coupled to the drive-voltage application device and the plurality of piezoelectric elements, the voltage distributor being configured to distribute the voltage applied from the drive-voltage application device to the plurality of piezoelectric elements.

19 . The polishing head system according to claim 18 , wherein the voltage distributor has a branch device configured to distribute the voltage applied from the drive-voltage application device to the plurality of piezoelectric elements, and a communication device coupled to the branch device and the drive-voltage application device.

20 . The polishing head system according to claim 19 , wherein the voltage distributor further has a plurality of plungers contacting the plurality of piezoelectric elements, and power distribution wires electrically coupling the plurality of plungers to the branch device.

21 . The polishing head system according to claim 18 , wherein the voltage distributor is detachably attached to the polishing head.

22 . The polishing head system according to claim 2 , wherein the polishing head further includes a temperature measuring device configured to measure a temperature of the plurality of piezoelectric elements.

23 . The polishing head system according to claim 2 , further comprising a vacuum line communicating with a workpiece contact surface of the polishing head.

24 . The polishing head system according to claim 2 , wherein:
the polishing head further includes a retainer ring located outwardly of the plurality of piezoelectric elements; and at least three workpiece chuck mechanisms fixed to the retainer ring.

25 . The polishing head system according to claim 2 , wherein the power supply unit is a DC power supply.

26 . A polishing apparatus for a workpiece, comprising:
a polishing table configured to hold a polishing pad; a polishing-liquid supply nozzle configured to supplying a polishing liquid to the polishing pad; and the polishing head system according to claim 1 .

27 . The polishing apparatus according to claim 26 , further comprising a film-thickness sensor configured to measure a film thickness of the workpiece, the film-thickness sensor being arranged in the polishing table.

28 . The polishing apparatus according to claim 27 , wherein the operation controller is configured to produce a film-thickness profile of the workpiece from measured values of the film thickness acquired by the film-thickness sensor, and to instruct the dr

Assignees

• Ebara Corp

Inventors

• Kobata Itsuki
• Yasuda Hozumi
• Yanai Akio
• Takahashi Nobuyuki
• Nakamura Takamasa
• Sakata Keisuke
• Takada Nobuyuki
• Yagi Yuji
• Takada Yasuhiro
• Watanabe Katsuhide

Classifications

• B24B37/34

  Accessories · CPC title

• B24B47/22

  Equipment for exact control of the position of the grinding tool or work at the start of the grinding operation · CPC title

• B24B47/20

  relating to feed movement · CPC title

• B24B47/12

  by mechanical gearing or electric power (B24B47/16 takes precedence) · CPC title

• B24B37/11 Primary

  Lapping tools · CPC title