Chemical mechanical polishing apparatus and method

• US 6,015,754 A
• Filed: 12/23/1997
• Issued: 01/18/2000
• Est. Priority Date: 12/25/1996
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kitamura, Toshihiko, Mase, Yasukazu, Kubota, Takeshi, Matsui, Yoshitaka
• Primary Examiner(s): Utech, Benjamin
• Assistant Examiner(s): GOUDREAU, GEORGE A
• Application Number:
  US08/996,695
• Time in Patent Office: 756 Days
• Field of Search: 156/345, 216/89, 216/86, 438/692, 438/17, 438/18
• US Class Current: 438/692
• CPC Class Codes: B24B 37/005 Control means for lapping machines or devices
• CPC Class Codes: B24B 49/10 involving electrical means B24B49/02, B24B49/08 take precedence
• CPC Class Codes: H01L 21/32115 Planarisation

Abstract

A CMP apparatus is used to subject a target surface of a semiconductor wafer to a polishing treatment, by moving the target surface and a polishing surface of a polishing cloth relative to each other while supplying a polishing liquid between the target surface and the polishing surface. Electric resistance is measured between pairs of measuring points arranged on opposite sides of dicing lines on the target surface, while subjecting the target surface to the polishing treatment. The polishing treatment is caused to be ended by comparing detected values of a changing rate in measured values of the electric property with a reference value set to correspond to an end point of the polishing treatment.

Claims

1. A chemical mechanical polishing apparatus comprising:

a polishing mechanism for subjecting a target surface of a target object to a polishing treatment, by moving said target surface and a polishing surface of a polishing member relative to each other while supplying a polishing liquid between said target surface and said polishing surface;

a measuring mechanism for measuring an electric property comprising electric resistance or a property representing said resistance between a pair of measuring points on said target surface, while subjecting said target surface to said polishing treatment;

a controller for causing said polishing treatment to be ended by comparing detected values derived from measured values of said electric property with a reference value set to correspond to an end point of said polishing treatment; and

wherein said controller processes said reference values and said detected values as values of a changing rate in said electric resistance.

2. The apparatus according to claim 1, wherein said measuring mechanism comprises a pair of electrodes arranged on opposite sides of said target surface to define said pair of measuring points.

3. The apparatus according to claim 1, wherein said pair of measuring points are rotated integratedly with said target object during said polishing treatment.

4. The apparatus according to claim 1, wherein said target surface is defined by a non-conductive layer, and said measuring mechanism is arranged such that said electric property comprises electric resistance or a property representing said resistance of a liquid layer, which is formed of said polishing liquid between said target surface and said polishing surface.

5. A chemical mechanical polishing method comprising the steps of:

subjecting a target surface of a target object to a polishing treatment, by moving said target surface and a polishing surface of a polishing member relative to each other while supplying a polishing liquid between said target surface and said polishing surface;

measuring an electric property comprising electric resistance or a property representing said resistance between a pair of measuring points on said target surface, while subjecting said target surface to said polishing treatment;

causing said polishing treatment to be ended by comparing detected values derived from measured values of said electric property with a reference value set to correspond to an end point of said polishing treatment; and

wherein said reference value and said detected values comprise values of a changing rate in said electric resistance.

6. The method according to claim 5, wherein said pair of measuring points are arranged on opposite sides of said target surface.

7. The method according to claim 5, wherein said pair of measuring points are rotated integratedly with said target object during said polishing treatment.

8. The method according to claim 5, wherein said target surface is defined by a non-conductive layer, and said electric property comprises electric resistance or a property representing said resistance of a liquid layer, which is formed of said polishing liquid between said target surface and said polishing surface.

9. A chemical mechanical polishing apparatus comprising:

a polishing mechanism for subjecting a target surface of a target object to a polishing treatment, by moving said target surface and a polishing surface of a polishing member relative to each other while supplying a polishing liquid between said target surface and said polishing surface;

a measuring mechanism for measuring an electric property comprising electric resistance or a property representing said resistance between a pair of measuring points on said target surface, while subjecting said target surface to said polishing treatment;

a controller for causing said polishing treatment to be ended by comparing detected values derived from measured values of said electric property with a reference value set to correspond to an end point of said polishing treatment;

wherein said target object comprises a semiconductor wafer, and said polishing mechanism includes a holder for holding said wafer;

wherein said target object includes a conductive layer defining said target surface, and an insulating layer arranged under said conductive layer and having a groove buried by part of said conductive layer, and said polishing treatment is performed by said polishing mechanism until said groove is exposed on said target surface at said end point;

wherein said groove of said insulating layer corresponds to a first dicing line extending across said wafer for cutting away a plurality of semiconductor devices to be formed on said wafer, from each other, and said first pair of measuring points are arranged on opposite ends of said dicing line; and

wherein said target object includes a second dicing line substantially equivalent to and perpendicular to said first dicing line, said measuring mechanism including a second pair of measuring points equivalent to said first pair of measuring points and arranged on opposite ends of said second dicing line, and said controller derives said detected values from measured values obtained by said first and second two pairs of measuring points.

11. The apparatus according to claim 9, wherein said controller processes said reference value and said detected values as values of said electric resistance.

12. The apparatus according to claim 9, wherein said controller processes said reference value and said detected values as values of a changing rate in said electric resistance.

13. The apparatus according to claim 9, wherein said measuring mechanism comprises a pair of electrodes arranged on opposite sides of said target surface to define each pair of measuring points.

14. The apparatus according to claim 9, wherein said pairs of measuring points are rotated integratedly with said target object during said polishing treatment.

10. A chemical mechanical polishing method comprising the steps of:

subjecting a target surface of a target object to a polishing treatment, by moving said target surface and a polishing surface of a polishing member relative to each other while supplying a polishing liquid between said target surface and said polishing surface;

measuring an electric property comprising electric resistance or a property representing said resistance between a pair of measuring points on said target surface, while subjecting said target surface to said polishing treatment;

causing said polishing treatment to be ended by comparing detected values derived from measured values of said electric property with a reference value set to correspond to an end point of said polishing treatment;

wherein said target object comprises a semiconductor wafer; and

wherein said target object includes a conductive layer defining said target surface, and an insulating layer arranged under said conductive layer and having a groove buried by part of said conductive layer, and said groove is exposed on said target surface at said end point.

15. The method according to claim 10, wherein said reference value and said detected values comprise values of said electric resistance.

16. The method according to claim 10, wherein said reference value and said detected values comprises values of a changing rate in said electric resistance.

17. The method according to claim 10, wherein said pair of measuring points are arranged on opposite sides of said target surface.

18. The method according to claim 10, wherein said pair of measuring points are rotated integratedly with said target object during said polishing treatment.

19. The method according to claim 10, wherein said groove of said insulating layer corresponds to a dicing line extending across said wafer for cutting away plurality of semiconductor devices to be formed on wafer, from each other, and said pair of measuring points are arranged on opposite ends of said dicing line.

20. The method according to claim 10, wherein target object includes a second dicing line substantially equivalent to and perpendicular to said dicing line, another pair of measuring points equivalent to said pair of measuring points are arranged on opposite ends of said second dicing line and said detected values are derived from measuring values obtained by said two pairs of measuring points.