Polishing apparatus

• US 6,764,381 B2
• Filed: 03/17/2003
• Issued: 07/20/2004
• Est. Priority Date: 01/17/2000
• Status: Expired due to Term

• Current Assignee: Ebara Corporation
• Original Assignee: Ebara Corporation
• Inventors: Kimura, Norio, Shimizu, Kazuo, Osawa, Hiroyuki, Isobe, Hideji
• Primary Examiner(s): Hail, III, Joseph J.
• Assistant Examiner(s): Thomas, David B.
• Application Number:
  US10/388,508
• Publication Number:
  US 20030171071A1
• Time in Patent Office: 491 Days
• Field of Search: 451/5, 451/6, 451/8, 451/9, 451/11, 451/283, 451/285, 451/287-289, 451/526, 156/345.12, 156/345.13
• US Class Current: 451/8
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 49/04 involving measurement of the workpiece at the place of grinding during grinding operation
• CPC Class Codes: B24B 49/10 involving electrical means B24B49/02, B24B49/08 take precedence
• CPC Class Codes: H01L 21/30625 With simultaneous mechanical treatment, e.g. mechanico-chemical polishing

Abstract

A polishing apparatus is used for polishing a substrate such as a semiconductor wafer, and has a sensor capable of continuously detecting the thickness of an electrically conductive layer. The polishing apparatus includes a polishing table having a polishing surface, and a top ring for holding and pressing the substrate against the polishing surface to polish the surface of the substrate. A sensor such as an eddy-current sensor is disposed below the polishing surface of the polishing table for measuring the thickness of a conductive layer formed on the surface of the substrate.

Claims

1. A polishing apparatus comprising:

a polishing table having a polishing surface;

a top ring for holding a substrate and pressing a surface of the substrate against said polishing surface to polish said surface of the substrate; and

an eddy-current sensor for measuring the thickness of a conductive layer formed on said surface of the substrate;

wherein said eddy-current sensor is used for monitoring the polishing process by monitoring the combined impedance of said eddy-current sensor and said conductive layer.

2. A polishing apparatus comprising:

a polishing table having a polishing surface;

a top ring for holding a substrate and pressing a surface of the substrate against said polishing surface to polish the surface of the substrate; and

at least one sensor for measuring the thickness of a conductive layer formed on the surface of the substrate;

wherein said at least one sensor is positioned so as to pass through an axis that passes through the center of the substrate and is perpendicular to the surface of the substrate when the substrate is held by said top ring and the surface of the substrate is pressed against said polishing surface.

3. The polishing apparatus of claim 2, wherein said at least one sensor comprises an eddy-current sensor.

4. The polishing apparatus of claim 2, wherein said at least one sensor comprises an optical sensor.

5. The polishing apparatus of claim 2, wherein said at least one sensor comprises two sensors comprising an eddy-current sensor and an optical sensor disposed adjacent to each other.

6. The polishing apparatus of claim 2, wherein said at least one sensor is disposed below said polishing surface of said polishing table.

7. A polishing apparatus comprising:

a rotatable polishing table having a polishing surface;

a top ring structured to hold a substrate and press a surface of the substrate against said polishing surface of said polishing table to polish the surface of the substrate during rotation of said polishing table; and

at least one sensor for measuring the thickness of a conductive layer formed on the surface of the substrate;

wherein said at least one sensor is positioned with said polishing table so as to pass beneath the surface of the substrate and along an arc so as to pass through an axis that passes through the center of the substrate and is perpendicular to the surface of the substrate when the substrate is held by said top ring, the surface of the substrate is pressed against said polishing surface and said polishing table is rotated; and

wherein said at least one sensor is operable to continuously measure the thickness of the conductive layer formed on the substrate in a substantially diametrical direction of the substrate as said at least one sensor passes beneath the surface of the substrate along the arc.

8. The polishing apparatus of claim 7, wherein said at least one sensor comprises an eddy-current sensor.

9. The polishing apparatus of claim 7, wherein said at least one sensor comprises an optical sensor.

10. The polishing apparatus of claim 7, wherein said at least one sensor comprises two sensors comprising an eddy-current sensor and an optical sensor disposed adjacent to each other.

11. The polishing apparatus of claim 7, wherein said at least one sensor is disposed below said polishing surface of said polishing table.