Control of chemical mechanical polishing pad conditioner directional velocity to improve pad life

• US 7,040,956 B2
• Filed: 04/29/2005
• Issued: 05/09/2006
• Est. Priority Date: 06/19/2001
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Paik, Young Joseph
• Primary Examiner(s): Rose, Robert A.
• Application Number:
  US11/118,711
• Publication Number:
  US 20050208879A1
• Time in Patent Office: 375 Days
• Field of Search: 451/5, 451/8, 451/9, 451/11, 451/21, 451/443, 451/444, 451/72, 451/56
• US Class Current: 451/5
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 37/042 operating processes therefor
• CPC Class Codes: B24B 49/03 according to the final size of the previously ground workpiece
• CPC Class Codes: B24B 49/18 taking regard of the presence of dressing tools
• CPC Class Codes: B24B 53/017 Devices or means for dressing, cleaning or otherwise conditioning lapping tools
• CPC Class Codes: G05B 19/00 Programme-control systems
• CPC Class Codes: G05B 19/19 characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
• CPC Class Codes: G05B 19/41865 characterised by job scheduling, process planning, material flow
• CPC Class Codes: G05B 2219/32053 Adjust work parameter as function of other cell
• CPC Class Codes: G05B 2219/32065 Synchronise set points of processes
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 21/67276 Production flow monitoring, e.g. for increasing throughput program-control systems per se G05B19/00, e.g. total factory control G05B19/418
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: Y02P 80/40 Minimising material used in manufacturing processes
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method, apparatus and medium of conditioning a planarizing surface includes installing a wafer to be polished in a chemical mechanical polishing (CMP) apparatus having a polishing pad and a conditioning disk, polishing the wafer under a first set of pad conditioning parameters selected to maintain wafer material removal rates with preselected minimum and maximum removal rates, determining a wafer material removal rate occurring during the polishing step, calculating updated pad conditioning parameters to maintain wafer material removal rates within the maximum and minimum removal rates, and conditioning the polishing pad using the updated pad conditioning parameters, wherein the updated pad conditioning parameters are calculated by a pad wear and conditioning model that predicts the wafer material removal rate of the polishing pad based upon the rotational speed and direction of the conditioning disk.

Claims

1. An apparatus for conditioning polishing pads used to planarize substrates by the removal of material therefrom, comprising:

a carrier assembly having an arm positionable over a planarizing surface of a polishing pad;

a conditioning disk attached to the carrier assembly;

and an actuator capable of controlling an operating parameter of the conditioning disk;

a controller operatively coupled to the actuator, the controller operating the actuator to adjust the operating parameter of the conditioning disk as a function of a pad wear and pad recovery model, the model

defining a wafer material removal rate as a function of pad conditioning parameters including at least one of conditioning disk rotation speed and direction.

2. The apparatus of claim 1, wherein the pad conditioning parameters of the pad wear and pad recovery model further comprises a conditioning parameter selected from the group consisting of duration of conditioning, frequency of conditioning and translational speed of conditioning disk during conditioning.

3. The apparatus of claim 1, wherein updated pad conditioning parameters are calculated by determining a difference between an output of the pad wear and pad recovery model and a wafer material removal rate measured for a wafer polished under a first set of pad conditioning parameters.

4. The apparatus of claim 3, wherein the updated pad conditioning parameters are updated according to the equation k=(k₁)+g*(k−

(k₁)), where k is a measured wafer material removal rate, k₁ is a calculated wafer material removal rate, g is the estimate gain, and (k−

(k₁), is the prediction error.

5. A computer readable medium comprising instructions being executed by a computer, the instructions including a computer-implemented software application for a chemical mechanical polishing process, the instructions for implementing the process comprising:

a) receiving data from a chemical mechanical polishing tool relating to the wafer removal rate of at least one wafer processed in the chemical mechanical polishing process; and

b) calculating, from the data of step (a), updated pad conditioning parameters within defined maximum and minimum values, wherein the updated pad conditioning parameters are calculated by determining the difference between an output of a pad wear and conditioning model and the data of step (a).

6. The medium of claim 5, wherein conditioning parameters of the pad wear and conditioning model are selected from the group consisting of disk rotation speed, direction, duration of conditioning, frequency of conditioning and translational speed of conditioning disk during conditioning.

7. The medium of claim 5, wherein the difference is adjusted using an estimate gain prior to calculating updated pad conditioning parameters.

8. The medium of claim 5, wherein calculating updated pad conditioning parameters in step (b) comprises executing a recursive optimization process.

9. The medium of claim 5, wherein the maximum value for wafer material removal rate is the saturation point of the wafer material removal rate vs. conditioning down force curve.

10. The medium of claim 5, wherein the maximum value for wafer material removal rate is the initial rate.

11. The medium of claim 5, wherein the minimum value for wafer material removal rate is defined by the minimum acceptable wafer polishing time.

21. The medium of claim 5, wherein the maximum value for the conditioning parameter is the value above which no incremental increase of the wafer removal rate is observed.

22. The medium of claim 21, wherein the minimum value for the conditioning parameter is the value that provides the minimum wafer removal rate.

12. A system for conditioning a planarizing surface in a chemical mechanical polishing (CMP) apparatus having a polishing pad against which a wafer is positioned for removal of material therefrom and a conditioning disk is positioned for conditioning of the polishing pad, comprising:

a) a pad wear and conditioning model that defines wafer material removal rate as a function of at least one pad conditioning parameters including rotation speed and direction of the conditioning disk;

b) polishing means for polishing a wafer in the CMP apparatus

c) measuring means for determining a wafer material removal rate; and

d) computing means for updating the at least one pad conditioning parameters based upon a wafer material removal rate measured using means of step (c) and the pad wear and conditioning model to maintain wafer material removal rates within the maximum and minimum removal rates.

13. The system of claim 12, wherein a first set of the at least one pad conditioning parameters are determined using the results of a design of experiment (DOE).

14. The system of claim 12, wherein the at least one pad conditioning parameters of the pad wear and conditioning model further comprises a conditioning parameter selected from the group consisting of frequency of conditioning, duration of conditioning, and translational speed of conditioning disk during conditioning.

15. The system of claim 12, wherein the step of calculating updated at least one conditioning parameters includes calculating parameters such that the parameter is within the determined minimum and maximum values.

16. The system of claim 12, wherein the updated at least one pad conditioning parameters are calculated by determining the difference between an output of the pad wear and conditioning model and the wafer material removal rate measured using the means of step (c).

17. The system of claim 16, wherein said difference is adjusted using an estimate gain prior to calculating updated conditioning parameters.

18. The system of claim 12, wherein the step of calculating updated at least one pad conditioning parameters in step (c) comprises executing a recursive optimization process.

19. The system of claim 12, wherein the maximum value for wafer material removal rate is the saturation point of the wafer material removal rate vs. conditioning down force curve.

20. The system of claim 12, wherein the maximum value for wafer material removal rate is the initial rate.

23. A system for conditioning a planarizing surface in a chemical mechanical polishing (CMP) apparatus having a polishing pad against which a wafer is positioned for removal of material therefrom and a conditioning disk is positioned for conditioning of the polishing pad, comprising:

a) a pad wear and conditioning model that defines wafer material removal rate as a function of at least one pad conditioning parameters including at least one of rotation speed and direction of the conditioning disk;

b) a polishing pad for polishing a wafer in the CMP apparatus

c) a tool for determining a wafer material removal rate; and

d) a computer-implemented software application with instructions for updating the at least one pad conditioning parameters based upon a wafer material removal rate measured using means of step (c) and the pad wear and conditioning model to maintain wafer material removal rates within the maximum and minimum removal rates.