Polishing apparatus

• US 6,878,044 B2
• Filed: 01/05/2004
• Issued: 04/12/2005
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Ebara Corporation
• Original Assignee: Ebara Corporation
• Inventors: Wakabayashi, Satoshi, Togawa, Tetsuji, Sekimoto, Masahiko, Hayama, Takuji, Saito, Kenichiro, Koga, Daisuke, Sakurai, Kunihiko, Takada, Nobuyuki
• Primary Examiner(s): Hail, III, Joseph J.
• Assistant Examiner(s): OJINI, EZIAMARA ANTHONY
• Application Number:
  US10/750,823
• Publication Number:
  US 20040137823A1
• Time in Patent Office: 463 Days
• Field of Search: 451/41, 451/42, 451/57, 451/63, 451/66, 451/73, 451/166, 451/259, 451264-274, 451285-290, 451392-397, 451/400, 451/67, 269/60
• US Class Current: 451/67
• CPC Class Codes: B24B 37/042 operating processes therefor
• CPC Class Codes: B24B 37/345 Feeding, loading or unloading work specially adapted to lapping
• CPC Class Codes: H01L 21/30625 With simultaneous mechanical treatment, e.g. mechanico-chemical polishing

Abstract

A polishing apparatus is used for polishing a workpiece such as a semiconductor wafer to a flat mirror finish. The polishing apparatus comprises a turntable having a polishing surface, a top ring for holding a workpiece and pressing the workpiece against the polishing surface to polish the workpiece, at least three cleaning apparatuses for cleaning polished workpieces, and a transfer structure for transferring the polished workpieces between at least three cleaning apparatuses. The polishing apparatus further includes a rotary transporter disposed in a position which can be accessed by said top rings and having a plurality of portions positioned on a predetermined circumference from a center of rotation of the rotary transporter for holding the workpieces.

Claims

1. A polishing apparatus comprising:

at least three load-unload stages each for placing a wafer cassette which accommodates a plurality of wafers;

a robot which moves along said at least three load-unload stages, for accessing said respective wafer cassettes;

a polishing unit for polishing a plurality of wafers simultaneously;

a cleaning and drying unit for cleaning and drying a polished wafer; and

a dummy wafer station for holding at least one dummy wafer or at least one quality control wafer.

2. A polishing apparatus according to claim 1, wherein said robot is movable along a rail disposed in said polishing apparatus.

3. A polishing apparatus according to claim 1, wherein said polishing unit comprises a plurality of top rings each for holding a respective wafer during polishing operation.

4. A polishing apparatus according to claim 3, wherein said polishing unit comprises a plurality of polishing tables each for providing a polishing surface for the wafer.

5. A polishing apparatus according to claim 1, further comprising another robot for transferring the wafer in a space between said load-unload stages and said polishing unit.

6. A polishing apparatus according to claim 1, wherein said cleaning and drying unit comprises at least three cleaning apparatuses for cleaning the wafer.

7. A polishing apparatus according to claim 1, wherein said load-unload stages, said robot, said cleaning and drying unit, and said polishing unit are disposed in order from one side of the polishing apparatus.

8. A polishing apparatus according to claim 1, wherein a partition is provided between said polishing unit and said cleaning and drying unit.

9. A polishing apparatus according to claim 1, wherein a partition is provided between said load-unload stages and said cleaning and drying unit.

10. A polishing apparatus according to claim 1, wherein said dummy wafer station holds said at least one dummy wafer, and said at least one dummy wafer is a substrate for use in stabilizing a polishing cloth in said polishing unit before a product wafer is processed.

11. A polishing apparatus according to claim 1, wherein said dummy wafer station holds said at least one quality control wafer, and said at least one quality control wafer is a substrate for confirming the status or condition of said polishing apparatus.

12. A polishing apparatus of claim 1, wherein said dummy wafer station comprises a substrate detection sensor for confirming the presence of a substrate in said dummy wafer station.

13. A polishing apparatus of claim 1, wherein said dummy wafer station is disposed below said load-unload stages.

14. A polishing apparatus comprising:

at least three load-unload stages each for placing a wafer cassette which accommodates a plurality of wafers;

a robot which moves along said at least three load-unload stages, for accessing said respective wafer cassettes;

a polishing unit for polishing a plurality of wafers simultaneously;

a cleaning and drying unit for cleaning and drying a polished wafer; and

a transporter for handling a plurality of the wafers at one time, and for moving a wafer to a preferable position below a top ring which holds the wafer during polishing operation;

wherein said robot and said cleaning and drying unit are disposed between said load-unload stages and said polishing unit.

15. A polishing apparatus according to claim 14, wherein said transporter transfers the wafers to a plurality of the top rings.

16. A polishing apparatus according to claim 14, further comprising a pusher disposed below said transporter for elevating the wafer on said transporter to the top ring.

17. A polishing apparatus comprising:

at least three load-unload stages each for placing a wafer cassette which accommodates a plurality of wafers;

a robot which moves along said at least three load-unload states for accessing said respective wafer cassettes;

a polishing unit for polishing a plurality of wafers simultaneously;

a cleaning and drying unit for cleaning and drying a polished wafer; and

a partition provided between said load-unload stales and said cleaning and drying unit,

wherein said robot and said cleaning and drying unit are disposed between said load-unload stages and said polishing unit, and

wherein a pressure of a space in which said cleaning and drying unit is disposed is adjusted so as to be lower than a pressure of a space in which said load-unload stages are disposed.

18. A polishing apparatus according to claim 17, wherein a pressure of a space in which said polishing unit is disposed is adjusted so as to be lower than a pressure of the space in which said cleaning and drying unit is disposed.