Polishing method using an abrading plate

• US 6,942,548 B2
• Filed: 07/30/2001
• Issued: 09/13/2005
• Est. Priority Date: 03/27/1998
• Status: Expired due to Fees

• Current Assignee: Ebara Corporation
• Original Assignee: Ebara Corporation
• Inventors: Hirokawa, Kazuto, Wada, Yutaka, Matsuo, Hisanori, Hiyama, Hirokuni
• Primary Examiner(s): Hail, III, Joseph J.
• Assistant Examiner(s): MCDONALD, SHANTESE L
• Application Number:
  US09/916,305
• Publication Number:
  US 20020006768A1
• Time in Patent Office: 1,506 Days
• Field of Search: 451/37, 451/41, 451/60, 451/287, 451/288, 451/443, 451/444, 451/446
• US Class Current: 451/41
• CPC Class Codes: B24B 37/042 operating processes therefor
• CPC Class Codes: B24B 37/245 Pads with fixed abrasives
• CPC Class Codes: B24B 53/017 Devices or means for dressing, cleaning or otherwise conditioning lapping tools
• CPC Class Codes: B24D 3/32 for porous or cellular structure
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

An abrading plate has a self-stopping capability such that when an object, such as a semiconductor wafer having a device structure that includes raised regions and depressed regions fabricated on the surface, is being polished, the raised regions are removed and polishing stops automatically. The abrading plate, to produce a flat and mirror polished surface on the an object, has abrasive particles having a chemical purity of not less than 90% and a particle size of not more than two micrometers, a binder material, and a given volume of porosity. A ratio of the abrasive particles and the binder material is not less than 1:0.5 by volume, and proportions of abrasive particles, a binder material and porosity are, respectively, not less than 10%, not more than 60% and 10-40% by volume. A surface is polished for a given duration with a liquid not containing abrasive particles so as to eliminate the raised regions and to obtain a flat surface. Additional surface removal is performed by supplying abrasive particles to the polishing interface to remove surface material uniformly from the entire surface.

Claims

1. A method for polishing an object by using an abrading surface made of abrasive particles and a binder, said method comprising:

polishing the object by the abrading surface while supplying a liquid not containing any abrasive particles for a determined time period; and

further polishing the object by the abrading surface while supplying abrasive particles so as to perform additional removal of a surface material to remove a specific film thickness.

2. A method according to claim 1, wherein said further polishing to remove the surface material is performed with the abrading surface by supplying a slurry containing abrasive particles to the abrading surface.

3. A method according to claim 1, wherein said further polishing to remove the surface material comprises:

polishing while concurrently dressing the abrading surface with a liquid not containing abrasive particles to thereby generate free abrasive particles therefrom.

4. A method according to claim 1, wherein the object is a semiconductor wafer having a raised and depressed pattern thereon.

5. A method according to claim 1, wherein the object is held by a same holder during and said further polishing.

6. A polishing apparatus for polishing a surface of an object, said polishing apparatus comprising:

a holder for holding the object;

an abrading surface comprising abrasive particles and a binder;

a mechanism for pressing the surface of the object to said abrading surface while producing a sliding motion over a polishing interface;

a device for supplying a liquid not containing abrasive particles to the polishing interface; and

a surface material removal device for performing additional material removal by supplying abrasive particles on said abrading surface, said surface material removal device being integrally mounted in said polishing apparatus.

7. A polishing apparatus according to claim 6, wherein said surface material removal device is a device for supplying a slurry containing abrasive particles to the polishing interface.

8. A polishing apparatus according to claim 6, wherein said surface material removal device is a device for dressing said abrading surface so as to release abrasive particles from said abrading surface.

9. A polishing apparatus according to claim 6, further comprising:

first polishing means for polishing while supplying a liquid not containing abrasive particles to the polishing interface; and

second polishing means for polishing while supplying a slurry containing abrasive particles to the polishing interface.

10. An apparatus according to claim 6, wherein said abrading surface comprises a surface of an abrading plate.

11. A method for polishing an object using an abrading surface made of abrasive particles and a binder binding the abrasive particles, said method comprising:

dressing the abrading surface to shape the abrading surface by a dresser prior to a polishing process;

pressing the object against the abrading surface; and

polishing the object by making a sliding motion between a surface of the object and the abrading surface, wherein

said dressing process comprises removing residual particles from the dressed abrading surface,

said removing process comprises washing the abrading surface using a brush while flowing a liquid thereon, and

the dresser comprises diamond particles.

12. A method according to claim 11, wherein the dresser comprises the diamond particles electro-deposited in a nickel base.

13. A method for polishing an object using an abrading surface made of abrasive particles and a binder binding the abrasive particles, said method comprising:

polishing a surface of the object by pressing the object against the abrading surface and making a sliding motion between the surface of the object and the abrading surface; and

dressing the abrading surface by a dresser for roughening the abrading surface during said polishing process to generate free abrasive particles from the abrading surface,

wherein said polishing process comprises conducting a first stage polishing without dressing, and conducting a second stage polishing with dressing.

14. A method according to claim 13, wherein said polishing process is conducted while supplying a liquid not containing abrasive particles.

15. A method according to claim 13, wherein the dresser comprises a diamond dresser.

16. An apparatus for polishing an object using an abrading surface made of abrasive particles and a binder binding the abrasive particles, said apparatus comprising:

a holder for holding the object;

a mechanism for pressing the object against the abrading surface and making a sliding motion between a surface of the object and the abrading surface;

a dresser for dressing the abrading surface prior to a polishing process to shape the abrading surface; and

a residual particles removing device for removing residual particles from the dressed abrading surface, wherein

said residual particles removing device comprises a brush for washing the abrading surface while flowing a liquid thereon, and

said dresser comprises diamond particles.

17. An apparatus according to claim 16, wherein said dresser comprises said diamond particles electro-deposited in a nickel base.

18. An apparatus for polishing an object using an abrading surface made of abrasive particles and a binder binding the abrasive particles, said apparatus comprising:

a holder for holding the object;

a mechanism for polishing a surface of the object by pressing the object against the abrading surface and making a sliding motion between a surface of the object and the abrading surface;

a dresser for dressing the abrading surface for roughening the abrading surface during the polishing process to generate free abrasive particles from the abrading surface; and

a controller for sending a signal for switching between a first stage polishing which is conducted without dressing, and a second stage polishing which is conducted with dressing.

19. An apparatus according to claim 18, wherein the polishing process is conducted while supplying a liquid not containing abrasive particles.

20. An apparatus according to claim 18, wherein the dresser comprises a diamond dresser.