Real-Time Parameter Tuning Using Wafer Thickness

• US 20080183412A1
• Filed: 01/30/2007
• Published: 07/31/2008
• Est. Priority Date: 01/30/2007
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Funk, Merritt, Lally, Kevin, Deshpande, Sachin
• Granted Patent: US 7,642,102 B2
• Time in Patent Office: Days
• US Class Current: 702/97
• CPC Class Codes: G01B 11/0616 of coating
• CPC Class Codes: G03F 7/70491 Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes
• CPC Class Codes: G03F 7/70525 Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure
• CPC Class Codes: G03F 7/70608 Monitoring the unpatterned workpiece, e.g. measuring thickness, reflectivity or effects of immersion liquid on resist
• CPC Class Codes: G03F 7/70691 Handling of masks or workpieces

Abstract

The invention can provide a method of processing a wafer using a Real-Time Parameter Tuning (RTPT) procedure to receive an input message that can include a pass-through message, a real-time feedforward message, or a real-time optimization message, or any combination thereof. The RTPT procedures can use real-time wafer thickness data to create, modify, and/or use measurement recipe data, measurement profile data, and/or measurement model data. In addition, RTPT procedures can use real-time wafer thickness data to create, modify, and/or use process recipe data, process profile data, and/or process model data.

Claims

1. A method of processing a wafer comprising:

receiving the wafer and wafer data, wherein the wafer is received by a measurement subsystem, a wafer state is established for the wafer, and the wafer data includes historical and/or real-time wafer thickness data;

receiving an input message including a pass-through message, or a real-time feedforward message, or any combination thereof, wherein the pass-through message includes historical wafer data and the real-time feedforward message includes real-time wafer thickness data;

creating, by a Transparent Coupling Device (TCD), real-time feedforward data using the real-time feedforward message, wherein the real-time feedforward data is created when input message includes a real-time feedforward message, and is not created when the input message does not include a real-time feedforward message, wherein the real-time feedforward data includes real-time wafer thickness data;

feed-forwarding the real-time feedforward data to a controller in the measurement subsystem when a feedforward state is a first value, and not feed-forwarding the real-time feedforward data when the feedforward state is a second value, wherein the feedforward state is the first value when the real-time feedforward data can be fed-forward before a measuring process is performed for the wafer, and wherein the feedforward state is the second value when the real-time feedforward data cannot be fed forward before the measuring process is performed for the wafer; and

either

creating a tuned measurement recipe, a tuned measurement profile, or a tuned measurement model, or any combination thereof using a Real-Time Parameter Tuning (RTPT) procedure that uses the real-time wafer thickness data as tuning data when a RTPT state is a first value and the input message includes a real-time feedforward message;

or

not creating the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof when the RTPT state is a second value and/or the input message does not include a real-time feedforward message.

2. The method as claimed in claim 1, further comprising:

measuring the wafer in the measurement subsystem using the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof when the RTPT state is the first value;

identifying the measured wafer as a tuned wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the tuned wafer as tuned measurement data.

3. The method as claimed in claim 2, further comprising:

creating by the measurement subsystem an un-tuned measurement recipe an un-tuned measurement profile, or an un-tuned measurement model, or any combination thereof when the feedforward state is the second value, and/or the RTPT state is the second value;

measuring the wafer in the measurement subsystem using the un-tuned measurement recipe, the un-tuned measurement profile, or the un-tuned measurement model, or any combination thereof when the RTPT state is the second value;

identifying the measured wafer as an un-tuned wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the un-tuned wafer as un-tuned measurement data.

4. The method as claimed in claim 1, further comprising:

modeling the wafer or modeling a measurement procedure for the wafer or modeling both of these in the measurement subsystem using the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof when the RTPT state is the first value.

5. The method as claimed in claim 1, wherein when the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof is created, the real-time wafer thickness data is used to determine one or more of:

a wafer radius for alignment procedure and/or an measurement procedure;

wafer curvature;

a contaminant level, a contamination probability, and/or an out-gassing rate;

an actual wafer thickness when the measurement occurs;

the amount of energy radiated by the wafer in an alignment and/or measurement chamber;

optical properties for the wafer and a calibration factor for the optical properties;

or properties of a photoresist layer.

6. The method as claimed in claim 1, further comprising:

creating by a Real-Time Optimizer (RTO) real-time feedforward data and optimization data using the real-time feedforward message when the input message includes a real-time feedforward message, wherein the real-time feedforward data and optimization data is created when the feedforward state is the first value, and is not created data when the feedforward state is a second value, wherein the optimization data includes wafer thickness data;

feed-forwarding the real-time feedforward data and optimization data to a controller in the measurement subsystem when the feedforward state is the first value, and not feed-forwarding the real-time feedforward data and optimization data when the feedforward state is the second value, wherein the feedforward state is the first value when the real-time feedforward data and/or optimization data can be fed-forward before a measurement process is performed for the wafer, and wherein the feedforward state is the second value when the real-time feedforward data and/or optimization data cannot be fed-forward before the measurement process is performed for the wafer; and

either

creating an optimized measurement recipe, an optimized measurement profile, or an optimized measurement model, or any combination thereof using a RTPT procedure that uses the real-time feedforward data and optimization data when the optimization state is the first value and the input message includes a feedforward message, or not creating, by a controller coupled to the RTO, the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof when the optimization state is the second value and/or the input message does not include a feedforward message.

7. The method as claimed in claim 6, further comprising:

measuring the wafer in the measurement subsystem using the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof when the RTPT state is the first value;

identifying the measured wafer as an optimized wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the optimized wafer as optimized measurement data.

8. The method as claimed in claim 7, further comprising:

creating by the measurement subsystem a non-optimized measurement recipe, a non-optimized measurement profile, or a non-optimized measurement model, or any combination thereof when the feedforward state is the first value, and the optimization state is the second value;

measuring the wafer in the measurement subsystem using the non-optimized measurement recipe, the non-optimized measurement profile, or the non-optimized measurement model, or any combination thereof when the RTPT state is the second value;

identifying the measured wafer as a non-optimized wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the non-optimized wafer as non-optimized measurement data.

9. The method as claimed in claim 6, further comprising:

modeling the wafer or modeling a measurement procedure or modeling both of these in the measurement subsystem using the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof when the optimization state is the first value.

10. The method as claimed in claim 1, wherein the measurement subsystem comprises a CD-Scanning Electron Microscopy (CDSEM) tool, a Transmission Electron Microscopy (TEM) tool, a focused ion beam (FIB) tool, an ODP tool, an Atomic Force Microscope (AFM) tool, or another optical metrology tool.

11. The method as claimed in claim 1, wherein the wafer is received by an integrated metrology (IM) tool in the measurement subsystem.

12. The method as claimed in claim 1, further comprising:

collecting data using a Manufacturing Execution System (MES), the collected data including the historical and real-time wafer thickness data;

creating additional real-time wafer thickness data, wherein the MES processes the collected data to create the additional real-time wafer thickness data;

creating a formatted message comprising the additional real-time wafer thickness data; and

sending the formatted message using the MES.

13. The method as claimed in claim 1, wherein the wafer state comprises a tuned variable (TV_n,m), an optimized variable (OV_n,m), a measured variable (MV_n,m), and a processed variable (PV_n,m), where n is the wafer number and m is a processing sequence number, the tuned variable (TV_n,m) is a first value when the wafer has been tuned and is a second value when the wafer has not been tuned, the optimized variable (OV_n,m) is a first value when the wafer has been optimized and is a second value when the wafer has not been optimized, the measured variable (MV_n,m) is a first value when the wafer has been measured and is a second value when the wafer has not been measured, and the processed variable (PV_n,m) is a first value when the wafer has been processed and is a second value when the wafer has not been processed.

31. A computer readable medium containing program instructions for execution on a computer system coupled to a semiconductor processing system, which when executed by the computer system, cause the semiconductor processing system to perform a process, comprising the steps of claim 1.

14. A method of processing a wafer comprising:

receiving the wafer and wafer data, wherein a wafer state is established for the wafer, and the wafer data includes thickness data;

receiving, by a controller, an input message including a pass-through message, or a real-time feedforward message, or any combination thereof;

creating feedforward recipe data, feedforward profile data, or feedforward model data, or any combination thereof using the real-time feedforward message when the input message includes a real-time feedforward message, wherein the feedforward recipe data, feedforward profile data, or feedforward model data, or any combination thereof is created when a feedforward state is a first value, and the feedforward recipe data, feedforward profile data, or feedforward model data, or any combination thereof is not created when the feedforward state is a second value;

sending the wafer to an integrated metrology (IM) tool when the sequencing state is a predetermined value corresponding to the IM tool;

sending the pass-through message to the IM tool when the input message includes the pass-through message and the sequencing state is said predetermined value, wherein the pass-through message is sent using a Transparent Coupling Device (TCD); and

either

feed-forwarding the feedforward recipe data, the feedforward profile data, or the feedforward model data, or any combination thereof using one or more TCDs coupled to the IM tool when a feedforward state is the first value and a sequencing state is the predetermined value, or not feed-forwarding the feedforward recipe data, the feedforward profile data, or the feedforward model data, or any combination thereof when the feedforward state is a second value.

15. The method as claimed in claim 14, further comprising:

creating a tuned wafer model using a first Real-Time Parameter Tuning (RTPT) procedure that uses the wafer thickness data, wherein the tuned wafer model is created when a RTPT state is the first value, and the tuned wafer model is not created when the RTPT state is a second value; and

storing the tuned wafer model.

16. The method as claimed in claim 15, further comprising:

creating tuned wafer profile data using a second RTPT procedure that uses the wafer thickness data and/or the tuned wafer model, wherein the tuned wafer profile data is created when the RTPT state is the first value, and the tuned wafer profile data is not created when the RTPT state is the second value; and

storing the tuned wafer profile data.

17. The method as claimed in claim 16, further comprising:

creating a tuned measurement recipe using a third RTPT procedure that uses the tuned wafer model, the tuned wafer profile data, or the wafer thickness data, or any combination thereof, wherein the tuned measurement recipe is created when the RTPT state is the first value, and the optimized recipe data is not created when the RTPT state is the second value;

measuring the wafer using the tuned measurement recipe when the RTPT state is the first value;

identifying the measured wafer as an tuned wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the tuned wafer as tuned measurement data.

18. The method as claimed in claim 14, further comprising:

creating an optimized wafer model using a first Real-Time Parameter Tuning (RTPT) procedure that uses the wafer thickness data and the pass-through message, wherein the optimized wafer model is created when an optimization state is a first value, and the optimized wafer model is not created when the optimization state is a second value, wherein the pass-through message includes optimization data; and

storing the optimized wafer model.

19. The method as claimed in claim 18, further comprising:

creating optimized wafer profile data using a second RTPT procedure that uses the optimization data, the wafer thickness data and/or the optimized wafer model, wherein the optimized wafer profile data is created when the optimization state is the first value, and the optimized wafer profile data is not created when the optimization state is the second value; and

storing the optimized wafer profile data.

20. The method as claimed in claim 19, further comprising:

creating an optimized measurement recipe using a third RTPT procedure that uses the optimized wafer model, the optimized wafer profile data, or the real-time wafer thickness data, or any combination thereof, wherein the optimized measurement recipe is created when the optimization state is the first value, and the optimized recipe data is not created when the optimization state is the second value;

measuring the wafer using the optimized measurement recipe when the optimization state is the first value;

identifying the measured wafer as an optimized wafer by changing the wafer state for the measured wafer; and

storing measurement data associated with the optimized wafer as optimized measurement data.

21. A method of processing a wafer comprising:

receiving the wafer and wafer data, wherein a wafer state is established for the wafer, and the wafer data includes historical and/or real-time wafer thickness data;

receiving, by a Real-Time Optimizer (RTO) an input message including a pass-through message, or a real-time feedforward message, or any combination thereof;

creating, by the RTO, optimized data using the real-time feedforward message when the input message includes a real-time feedforward message, wherein the optimized data is created when an optimization state is a first value, and the optimized data is not created when the optimization state is a second value;

sending the wafer to an internal measurement subsystem when a sequencing state is a predetermined value;

sending the pass-through message to the internal measurement subsystem when the input message includes the pass-through message and/or when a pass-through state is a first value and the sequencing state is the predetermined value, and not sending the pass-through message to the internal measurement subsystem when the input message does not include the pass-through message, wherein the pass-through message is sent using a Transparent Coupling Device (TCD); and

either

sending the optimized data to the internal measurement subsystem when the feedforward state is the first value and the sequencing state is the predetermined value, or not sending the optimized data to the internal measurement subsystem when the feedforward state is the second value.

22. The method as claimed in claim 21, further comprising:

creating an optimized measurement recipe, an optimized measurement profile, or an optimized measurement model, or any combination thereof using a Real-Time Parameter Tuning (RTPT) procedure; and

sending the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof to the internal measurement subsystem with the optimized data wherein the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof is created using the real-time feedforward message when the input message includes a real-time feedforward message and the optimization state is the first value, and the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof is not created when the optimization state is the second value, wherein the real-time feedforward message includes real-time wafer thickness data.

23. The method as claimed in claim 22, further comprising:

measuring by the internal measurement subsystem the wafer using the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof when an update state is a first value and the optimization state is the first value;

identifying the measured wafer as an optimized wafer by changing the wafer state for the measured wafer; and

identifying measurement data associated with the optimized wafer as optimized measurement data.

24. The method as claimed in claim 23, further comprising:

measuring by the internal measurement subsystem the wafer using a non-optimized measurement recipe when the update state is the second value, and the optimization state is the second value;

identifying the measured wafer as a non-optimized wafer by changing the wafer state for the measured wafer; and

identifying measurement data associated with the non-optimized wafer as non-optimized measurement data.

25. The method as claimed in claim 21, further comprising:

creating an optimized measurement recipe, an optimized measurement profile, or an optimized measurement model, or any combination thereof using a Real-Time Parameter Tuning (RTPT) procedure that uses the optimized data;

measuring by the internal measurement subsystem the wafer using the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof when an update state is a first value, and the optimization state is the first value;

identifying the measured wafer as an optimized wafer by changing the wafer state for the measured wafer; and

identifying measurement data associated with the optimized wafer as optimized measurement data.

26. The method as claimed in claim 25, further comprising:

measuring by the internal measurement subsystem, the wafer using a non-optimized measurement recipe when the update state is a second value, and/or the optimization state is a second value;

identifying the measured wafer as a non-optimized wafer by changing the wafer state for the measured wafer; and

identifying measurement data associated with the non-optimized wafer as non-optimized measurement data.

27. The method as claimed in claim 22, wherein when the optimized measurement recipe, the optimized measurement profile, or the optimized measurement model, or any combination thereof is created, the real-time wafer thickness data is used to determine one or more of:

a wafer radius for alignment procedure and/or a measurement procedure;

wafer curvature;

a contaminant level, a contamination probability, and/or an out-gassing rate;

actual wafer thickness when the measurement occurs;

amount of energy radiated by the wafer in an alignment and/or measurement chamber;

optical properties for the wafer;

a calibration factor for the optical properties the characteristics of a photoresist layer;

or the correct location for a measurement site on the wafer.

28. The method as claimed in claim 21, wherein said predetermined value is a fourth value, the method further comprising:

sending the wafer to a lithography subsystem when the sequencing state is a first value;

sending the wafer to an etch subsystem when the sequencing state is a second value;

sending the wafer to a deposition subsystem when the sequencing state is a third value;

sending the wafer to an external measurement tool when the sequencing state is a fifth value, and

sending the wafer to a transfer subsystem when the sequencing state is a sixth value.

29. A system for processing a wafer comprising:

a measurement subsystem configured to receive the wafer and wafer data, wherein a wafer state is established for the wafer, and the wafer data includes historical and/or real-time wafer thickness data, and to receive an input message including a pass-through message, or a real-time feedforward message, or any combination thereof, wherein the pass-through message includes historical wafer data and the real-time feedforward message includes real-time wafer thickness data;

a Transparent Coupling Device (TCD) coupled to the measurement subsystem, and configured to create real-time feedforward data using the real-time feedforward message when the input message includes a real-time feedforward message, wherein the real-time feedforward data is created when a feedforward state is a first value, and is not created when the feedforward state is a second value, wherein the real-time feedforward data includes real-time wafer thickness data;

feed-forward the real-time feedforward data to the measurement subsystem when the feedforward state is the first value, and not feed-forward the real-time feedforward data when the feedforward state is a second value, wherein the feedforward state is the first value when the real-time feedforward data can be fed-forward before an measurement process is performed for the wafer, and wherein the feedforward state is the second value when the real-time feedforward data cannot be fed-forward before the measurement process is performed for the wafer; and

a controller that creates a tuned measurement recipe, a tuned measurement profile, or a tuned measurement model, or any combination thereof using a Real-Time Parameter Tuning (RTPT) procedure that uses the real-time feedforward data when a RTPT state is a first value, and does not create the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof when the RTPT state is a second value.

30. The system as claimed in claim 29, wherein the measurement subsystem comprises means for measuring the wafer using the tuned measurement recipe, the tuned measurement profile, or the tuned measurement model, or any combination thereof when the RTPT state is the first value, and for identifying the measured wafer as a tuned wafer by changing a wafer state for the wafer, and for storing measurement data associated with the tuned wafer as tuned measurement data.

32. A method of performing optical measurements on a wafer comprising:

processing an input signal to obtain non-tuning data including a measurement recipe for use in the optical measurement system;

performing an optical measurement based on the measurement recipe at optical measurement hardware of the measurement system to obtain an optical diffraction signal from a measurement site on said wafer;

obtaining tuning data an optical analysis system of the measurement system; and

calculating a measurement result based on said optical diffraction signal and said tuning data.

33. The method of claim 32, wherein said processing is performed by a processor of the optical measurement system.

34. The method of claim 32, wherein said processing is performed by a TCD associated with the optical measurement system, said TCD being either external to the optical measurement system or an integral part of the optical measurement system.

35. The method of claim 32, wherein said performing comprises performing an optical measurement based on a measurement recipe including measurements for a plurality of measurement sites on the semiconductor wafer, wherein a plurality of diffraction signals corresponding to said plurality of measurement sites are obtained as a result of performance of the recipe.

36. The method of claim 32, wherein said obtaining comprises obtaining external tuning data including wafer characteristic data from said input message.

37. The method of claim 36, wherein said wafer characteristic data of the external tuning data comprises end data measured and/or calculated by a subsystem external to the optical measurement tool.

38. The method of claim 32, wherein said obtaining comprises obtaining internal tuning data including wafer characteristic data created during said measurement in the optical measurement hardware.

39. The method of claim 32, wherein said tuning data comprises n&

k values determined by either the optical measurement system or a system other than the optical measurement system or both.