Slurry recycling apparatus and slurry recycling method for chemical-mechanical polishing technique

• US 6,183,352 B1
• Filed: 08/25/1999
• Issued: 02/06/2001
• Est. Priority Date: 08/28/1998
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Corporation
• Inventors: Kurisawa, Shuu
• Primary Examiner(s): Gerrity, Stephen F.
• Assistant Examiner(s): MCDONALD, SHANTESE L
• Application Number:
  US09/382,640
• Time in Patent Office: 531 Days
• Field of Search: 451/36, 451/60, 451/87, 451/88, 451/99, 451/446, 451/447, 210/167, 210/96.1, 210/416.1, 210/739
• US Class Current: 451/87
• CPC Class Codes: B24B 37/04 designed for working plane surfaces
• CPC Class Codes: B24B 57/02 for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents

Abstract

A first pump collects used slurry which is employed for a CMP technique. A new slurry supply device supplies new slurry having a concentration higher than a concentration of the used slurry, to the used slurry. A sensor measures a concentration of recycled slurry produced by mixing the used slurry with the new slurry. The new slurry supply device stops supplying the new slurry, in a case where the concentration which the sensor measures is equal to or above a predetermined value. A second pump supplies recycled slurry onto a polishing stage, after the used slurry is completely recycled.

Claims

1. A slurry recycling apparatus for chemical-mechanical polishing (CMP) technique, comprising:

a first pump which collects used slurry employed for a CMP technique, from a chemical-mechanical polishing apparatus;

a new slurry supply device which supplies, to the used slurry, new slurry having a concentration higher than a concentration of the used slurry;

a sensor which measures a concentration of recycled slurry produced by mixing the used slurry with the new slurry; and

a second pump which supplies the recycled slurry to the chemical-mechanical polishing apparatus,

wherein said new slurry supply device stops supplying the new slurry, in a case where the concentration of the recycled slurry which said sensor measures is equal to or above a predetermined value, and

said second pump supplies the recycled slurry to the chemical-mechanical polishing apparatus, after the slurry is completely recycled.

2. The slurry recycling apparatus for a CMP technique according to claim 1, further comprising:

a first tank which contains the used slurry collected by said first pump; and

a mixer which is arranged in said first tank,

wherein said new slurry supply device supplies the new slurry into said first tank,

said mixer produces the recycled slurry by mixing the used slurry with the new slurry supplied into said first tank, and

said second pump supplies the recycled slurry contained in said first tank to the chemical-mechanical polishing apparatus, after the slurry is completely recycled.

3. The slurry recycling apparatus for a CMP technique according to claim 2, further comprising:

a first filtration unit which removes unnecessary components from the used slurry collected by said first pump; and

a second filtration unit which removes unnecessary components from the recycled slurry to be supplied to the chemical-mechanical polishing apparatus.

4. The slurry recycling apparatus for a CMP technique according to claim 3, further comprising a chemical component supply device which supplies, into said first tank, chemical components for recycling the used slurry.

5. The slurry recycling apparatus for a CMP technique according to claim 4, further comprising:

at least one second tank;

a first valve which selects a predetermined tank containing the used slurry collected by said first pump, from said first tank and said at least one second tank, and which conducts the used slurry to the predetermined tank; and

a second valve which selects a predetermined tank into which the new slurry is supplied by said new slurry supply device, from said first tank and said at least one second tank, and which conducts the new slurry to the predetermined tank,

wherein said mixer produces the recycled slurry in at least one of said first tank and said at least one second tank,

said first pump collects the used slurry in at least one of said first tank and said at least one second tank, in which the recycled slurry is not being produced by said mixer.

6. The slurry recycling apparatus for a CMP technique according to claim 5, further comprising a chemical-mechanical polishing apparatus which polishes a to-be-polished object.

7. The slurry recycling apparatus for a CMP technique according to claim 1, further comprising:

a first tank;

a tube which conducts used slurry collected by said first pump to said first tank; and

a third pump which forms a circulation path between said first tank and said tube,

wherein said new slurry supply device supplies the new slurry to the used slurry which flows into said tube,

said third pump produces the recycled slurry by causing the used slurry and the new slurry to circulate between said first tank and said tube, and

said second pump supplies the recycled slurry contained in said first tank to the chemical-mechanical polishing apparatus, after the slurry is completely recycled.

8. The slurry recycling apparatus for a CMP technique according to claim 7, further comprising a chemical component supply device which supplies chemical components for recycling the used slurry to the used slurry which flows into said tube.

9. The slurry recycling apparatus for a CMP technique according to claim 8, further comprising:

at least one second tank;

a first valve which selects a predetermined tank into which the used slurry collected by said first pump is supplied, from said first tank and said at least one second tank, and which conducts the used slurry to the predetermined tank;

a second valve which selects at least one of said first tank and said at least one second tank, through which the used slurry and the new slurry are caused to circulate by said third pump; and

a third valve which selects a predetermined tank containing the recycled slurry which said second pump supplies to the chemical-mechanical polishing apparatus,

wherein said second pump supplies, to the chemical-mechanical polishing apparatus, the recycled slurry contained in at least one of said first tank and said at least one second tank, and

said third pump produces the recycled slurry by causing the used slurry and the new slurry to circulate between said tube and at least one tank from which the recycled slurry is not being supplied by said second pump.

10. The slurry recycling apparatus for a CMP technique according to claim 9, further comprising a chemical-mechanical polishing apparatus which polishes a to-be-polished object.

11. A slurry recycling method for a CMP technique, comprising:

collecting used slurry employed for a CMP technique, from a CMP apparatus;

supplying, to the used slurry, new slurry having a concentration higher than a concentration of the used slurry;

producing recycled slurry by mixing the used slurry and the new slurry;

measuring a concentration of the recycled slurry; and

supplying the recycled slurry to the CMP apparatus,

wherein said supplying the new slurry includes stopping supplying the new slurry, in a case where a concentration of the recycled slurry is equal to or above a predetermined value, and

said supplying the recycled slurry includes supplying the recycled slurry to the chemical-mechanical polishing apparatus, in a case where the slurry is completely recycled.

12. The slurry recycling method for a CMP technique according to claim 11, further comprising:

removing unnecessary components from the collected used slurry; and

removing unnecessary components from the recycled slurry which is supplied to the chemical-mechanical polishing apparatus.

13. The slurry recycling method for a CMP technique according to claim 12, further comprising supplying chemical components for recycling the used slurry to the used slurry.

14. The slurry recycling method for a CMP technique according to claim 13, wherein:

said producing the recycled slurry includes producing the recycled slurry in at least one of a plurality of tanks; and

said collecting the used slurry includes collecting the used slurry in at least one tank, in which the recycled slurry is not being produced.

15. The slurry recycling method for a CMP technique according to claim 13, wherein:

said supplying the recycled slurry includes supplying the recycled slurry from at least one of a plurality of tanks, to the CMP apparatus; and

said producing the recycled slurry includes producing the recycled slurry in at least one tank, from which the recycled slurry is not being supplied.