Endpoint detection method and apparatus which utilize an endpoint polishing layer of catalyst material

• US 6,258,205 B1
• Filed: 03/24/2000
• Issued: 07/10/2001
• Est. Priority Date: 06/30/1998
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Chisholm, Brynne K., Miller, Gayle W., Shelton, Gail D.
• Primary Examiner(s): Lund, Jeffrie R.
• Assistant Examiner(s): MACARTHUR, SYLVIA
• Application Number:
  US09/534,652
• Time in Patent Office: 473 Days
• Field of Search: 156/345, 451/66, 451/39, 451/282, 451/259, 513/06, 216/84, 216/88, 216/89, 216/90, 216/93, 216/95, 222/26, 222/190, 118/688, 118/689, 438/5
• US Class Current: 156/345.16
• CPC Class Codes: B24B 37/04 designed for working plane surfaces
• CPC Class Codes: B24B 49/00 Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation B24B33/06, B24B37/005 take precedence; if applicable to other machine tools, B23Q15/00 - B23Q17/00 take precedence
• CPC Class Codes: B24B 55/12 Devices for exhausting mist of oil or coolant; Devices for collecting or recovering materials resulting from grinding or polishing, e.g. of precious metals, precious stones, diamonds or the like
• CPC Class Codes: B24B 57/02 for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step

Abstract

An apparatus for planarizing a semiconductor wafer having a polishing endpoint layer that includes a catalyst material is disclosed. The apparatus is operable to detect the endpoint based upon the chemical slurry whether a catalytic reaction has occurred due to the polishing platen removing a portion of the catalyst material from the wafer.

Claims

1. An apparatus for polishing a semiconductor wafer down to a catalyst material of said wafer, said wafer having a first side and a second side, comprising:

a polishing platen having a polishing surface;

a wafer carrier configured to (i) engage said wafer by said second side of said wafer and (ii) press said first side of said wafer against said polishing surface of said polishing platen;

a slurry supply system configured to apply a chemical slurry to said first side of said wafer which (i) facilities removal of material from said wafer, and (ii) receives said material removed from said wafer carrier, wherein said polishing platen and said wafer carrier are configured to rub said first side of said wafer against said polishing surface in the presence of said chemical slurry in order to remove said material from said wafer; and

a polishing endpoint detector that is operable to (i) detect based upon said chemical slurry whether a catalytic reaction has occurred due to said polishing platen removing a portion of said catalyst material from said wafer, and (ii) cause said polishing of said wafer to terminate in response to detecting said catalytic reaction.

2. The apparatus of claim 1, wherein said polishing endpoint detector comprises:

a slurry extractor that is operable to extract said chemical slurry from said polishing platen to a testing area.

3. The apparatus of claim 2, further comprising:

a reagent supply system which is operable to add a reagent to said chemical slurry in said testing area which catalytically reacts with said chemical slurry when said chemical slurry includes said catalyst material.

4. The apparatus of claim 2, further comprising:

a reagent supply system which is operable to add a plurality of reagents to said chemical slurry in said testing area which catalytically react when said chemical slurry includes said catalyst material.

5. The apparatus of claim 1, further comprising:

a reagent supply system which is operable to add a reagent to said chemical slurry, wherein said reagent catalytically reacts when said chemical slurry includes said catalyst material.

6. The apparatus of claim 5, wherein:

said reagent is t-butyl bromide, and

said catalyst material is selected from a group of ions comprising silver ions and mercury ions.

7. The apparatus of claim 1, further comprising:

a reagent supply system which is operable to add a plurality of reagents to said chemical slurry, wherein said plurality of reagents catalytically react when said chemical slurry includes said catalyst material.

8. The apparatus of claim 1, further comprising:

a reagent supply system which is operable to add a reagent to said chemical slurry after said wafer carrier and said polishing platen have rubbed said first side of said wafer for a predetermined period.