System for real-time control of semiconductor wafer polishing

• US 6,338,667 B2
• Filed: 12/28/2000
• Issued: 01/15/2002
• Est. Priority Date: 08/25/1993
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Sandhu, Gurtej S., Doan, Trung Tri
• Primary Examiner(s): Eley, Timothy V.
• Application Number:
  US09/752,217
• Publication Number:
  US 20010001755A1
• Time in Patent Office: 383 Days
• Field of Search: 437/7, 437/8, 437/225, 437/249, 451/5, 451/6, 451/7, 451/8, 451/9, 451/10, 451/41, 451/285, 451/286, 451/287, 451/288, 451/289, 451/290
• US Class Current: 451/5
• CPC Class Codes: B23Q 15/013 Control or regulation of feed movement B23Q15/12 takes precedence
• CPC Class Codes: B23Q 15/12 Adaptive control, i.e. adjusting itself to have a performance which is optimum according to a preassigned criterion
• CPC Class Codes: B24B 13/015 of television picture tube viewing panels, headlight reflectors or the like
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 37/015 Temperature control
• CPC Class Codes: B24B 37/107 in a rotary movement only, about an axis being stationary during lapping
• CPC Class Codes: B24B 37/12 Lapping plates for working plane surfaces
• CPC Class Codes: B24B 37/205 provided with a window for inspecting the surface of the work being lapped
• CPC Class Codes: B24B 49/003 involving acoustic means
• CPC Class Codes: B24B 49/02 according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent B24B49/12 takes precedence
• 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: B24B 49/12 involving optical means
• CPC Class Codes: B24B 57/02 for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/34403 RTI real time, kernel, processing
• CPC Class Codes: G05B 2219/37398 Thickness
• CPC Class Codes: G05B 2219/37602 Material removal rate
• CPC Class Codes: G05B 2219/45026 Circuit board, pcb
• CPC Class Codes: G05B 2219/45199 Polish
• CPC Class Codes: G05B 2219/45232 : CMP chemical mechanical polishing of wafer
• CPC Class Codes: G05B 2219/49052 : Accessory, coolant
• CPC Class Codes: G05B 2219/49057 : Controlling temperature of workpiece, tool, probe holder

Abstract

A system for polishing a semiconductor wafer, the system comprising a wafer polishing assembly for polishing a face of a semiconductor wafer at a polishing rate and a polishing uniformity, the wafer polishing assembly including a platen subassembly defining a polishing area, and a polishing head selectively supporting a semiconductor wafer and holding a face of the semiconductor wafer in contact with the platen subassembly to polish the wafer face; and a controller selectively adjusting one of a plurality of adjustable polishing parameters during polishing of the wafer.

Claims

1. A polishing system comprising:

a wafer polishing assembly for polishing a face of a semiconductor wafer at a polishing rate and a polishing uniformity, the wafer polishing assembly including a platen subassembly defining a polishing area, a polishing head shaft, and a polishing head supported by the polishing head shaft for rotation relative to the polishing head shaft, the polishing head being configured to support the semiconductor wafer, the wafer polishing assembly further including a polishing head displacement mechanism supporting the polishing head shaft relative to the platen subassembly and configured to translate the polishing head shaft relative to the platen subassembly along a polishing path which is variable between a linear polishing path and a non-linear polishing path, to cause the polishing head to polish the wafer face; and

a controller configured to adjust the polishing path.

2. The polishing system of claim 1, wherein the polishing head includes pressure applicators for applying various localized pressures on individual regions of the semiconductor wafer to conform the wafer face to a selected contour.

3. The polishing system of claim 1, further comprising a polish control subsystem for monitoring polishing rates at various regions of the semiconductor wafer and adjusting platen velocity.

4. The polishing system of claim 1, wherein the polishing head includes pressure applicators for applying various localized pressures on individual regions of the semiconductor wafer to conform the wafer face to a selected contour, the system further comprising a polish control subsystem for monitoring polishing rates at various regions of the semiconductor wafer and adjusting platen velocity.

5. The polishing system of claim 1, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior; and

a heating element proximate the fluid passage.

6. The polishing system of claim 1, wherein the controller is operably coupled to the wafer polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the wafer polishing assembly;

and further comprising a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the wafer polishing assembly in response to the control information from the processor to control wafer to wafer uniformity.

7. The polishing system of claim 1, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior; and

a heating element proximate the fluid passage, wherein the controller is operably coupled to the wafer polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the wafer polishing assembly; and

a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the wafer polishing assembly in response to the control information from the processor to control wafer to wafer uniformity.

8. The polishing system of claim 1, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior;

a heating element proximate the fluid passage, wherein the controller is operably coupled to the wafer polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the wafer polishing assembly; and

a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the wafer polishing assembly in response to the control information from the processor to control wafer to wafer uniformity.

9. A polishing system controlling at least one operational parameter of a polishing process to control wafer to wafer uniformity of the process, the system comprising:

a wafer polishing assembly configured to polish a face of a semiconductor wafer at a polishing rate and a polishing uniformity, the wafer polishing assembly including a platen rotatable about a first axis and having a hollow interior, a polishing head which supports the semiconductor wafer for rotation about a second axis, and a polishing head displacement mechanism which moves the polishing head and wafer across the platen, the wafer polishing assembly having a plurality of controllable operational parameters that upon variation change the polishing rate and polishing uniformity;

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior;

a heating element proximate the fluid passage;

a controller operably coupled to the wafer polishing assembly for monitoring and managing at least one of the operational parameters of the wafer polishing assembly;

a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the wafer polishing assembly in response to the control information from the processor to control wafer to wafer uniformity.

10. A polishing system comprising:

a rotatable platen subassembly defining a polishing area;

a drive mechanism coupled to rotate the platen subassembly at a platen velocity;

a polishing head configured to support a semiconductor wafer and hold a face of the semiconductor wafer in contact with the platen subassembly to polish the wafer face whereby individual regions of the wafer face have different polishing rates, the polishing head being movable across the platen subassembly;

a heating element supported by the polishing head;

the polishing head having pressure applicators for applying various localized pressures on the individual regions of the semiconductor wafer to conform the wafer face to a selected contour; and

a polish control subsystem for monitoring the polishing rates at various regions of the semiconductor wafer and adjusting the platen velocity.

11. A polishing system comprising:

a polishing assembly for polishing a face of a workpiece at a polishing rate and a polishing uniformity, the polishing assembly including a platen subassembly defining a polishing area, a polishing head shaft, and a polishing head supported by the polishing head shaft for rotation relative to the polishing head shaft, the polishing head being configured to support the workpiece, the polishing assembly further including a polishing head displacement mechanism supporting the polishing head shaft relative to the platen subassembly and configured to translate the polishing head shaft relative to the platen subassembly along a polishing path that is variable between a linear polishing path and a non-linear polishing path; and

a controller configured to adjust the polishing path.

12. The polishing system of claim 11, wherein the polishing head includes pressure applicators for applying various localized pressures on individual regions of the workpiece face to conform the face to a selected contour.

13. The polishing system of claim 11, further comprising a polish control subsystem for monitoring polishing rates at various regions of the workpiece face and adjusting platen velocity.

14. The polishing system of claim 11, wherein the polishing head includes pressure applicators for applying various localized pressures on the individual regions of the workpiece face to conform the face to a selected contour, the system further comprising a polish control subsystem for monitoring polishing rates at various regions of the face and adjusting platen velocity.

15. The polishing system of claim 11, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior; and

a heating element proximate the fluid passage.

16. The polishing system of claim 11, wherein the controller is operably coupled to the polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the polishing assembly;

and further comprising a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the polishing assembly in response to the control information from the processor to control workpiece to workpiece polishing uniformity.

17. The polishing system of claim 11, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior; and

a heating element proximate the fluid passage, wherein the controller is operably coupled to the polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the polishing assembly; and

a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the polishing assembly in response to the control information from the processor to control workpiece to workpiece polishing uniformity.

18. The polishing system of claim 11, wherein the platen includes a hollow interior, the system further comprising:

a fluid passage in fluid communication with the hollow interior;

a pump in fluid communication with the fluid passage and conducting fluid through the hollow interior;

a heating element proximate the fluid passage, wherein the controller is operably coupled to the polishing assembly for monitoring and managing at least one of a plurality of operational parameters of the polishing assembly; and

a processor operably coupled to the controller for determining a set of desired operational parameters based on the monitored operational parameters and outputting control information indicative of the desired operational parameters to the controller, the controller adjusting at least one of the operational parameters of the polishing assembly in response to the control information from the processor to control workpiece to workpiece polishing uniformity.

19. The polishing system of claim 11, wherein the polishing assembly is a semiconductor wafer polishing assembly configured to polish a face of a semiconductor wafer.