Dynamic metrology schemes and sampling schemes for advanced process control in semiconductor processing

• US 20080133163A1
• Filed: 12/31/2007
• Published: 06/05/2008
• Est. Priority Date: 06/19/2001
• Status: Active Grant

• Current Assignee: Alexander T. Sohwarm, Arulkumar P. Shanmugasundram
• Original Assignee: Alexander T. Sohwarm, Arulkumar P. Shanmugasundram
• Inventors: Sohwarm, Alexander T., Shanmugasundram, Arulkumar P.
• Granted Patent: US 7,725,208 B2
• Time in Patent Office: Days
• US Class Current: 702/83
• 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 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y02P 90/80 Management or planning

Abstract

Systems, methods and mediums are provided for dynamic adjustment of sampling plans in connection with a wafer (or other device) to be measured. The invention adjusts the frequency and/or spatial resolution of measurements on an as-needed basis when one or more events occur that are likely to indicate an internal or external change affecting the manufacturing process or results. The dynamic metrology plan adjusts the spatial resolution of sampling within-wafer by adding, subtracting or replacing candidate points from the sampling plan, in response to certain events which suggest that additional or different measurements of the wafer may be desirable. Further, the invention may be used in connection with adjusting the frequency of wafer-to-wafer measurements.

Claims

1. A computer-implemented method of measuring at least one manufacturing characteristic for at least one product manufactured by a manufacturing process, comprising:

providing information representative of a set of candidate points to be measured by the manufacturing process on the at least one product;

executing, by the manufacturing process, a plan for performing measurements on the at least one product to measure the at least one manufacturing characteristic, the plan defining the measurements to be made responsive to the set of candidate points;

detecting one of a plurality of events or a lack of one of the plurality of events indicating a change in the manufacturing process, the change pertaining to at least one of;

detecting a fault in the manufacturing process, and detecting a variation in a measurement of the at least one product;

determining whether to take more or fewer measurements based on the detected event or lack of the event; and

adjusting the plan, in real time, to increase a spatial density of within-product measurements upon determining to take fewer measurements, and to decrease the spatial density of within-product measurements upon determining to take more measurements.

2. The method of claim 1, wherein the product is a semi-conductor wafer and the manufacturing process is an automated semi-conductor manufacturing process.

3. The method of claim 1, wherein the plan further comprises information representative of a metrology recipe.

4. The method of claim 1, wherein the plan defines at least one region on the product, each of the candidate points corresponding to the at least one region.

5. The method of claim 1, wherein the adjusting the plan comprises:

determining at least one region corresponding to the detected change;

selecting at least one measurement responsive to candidate points corresponding to the determined region;

assigning the selected at least one measurement as an additional measurement to be performed or as a measurement to be removed under the plan; and

revising at least one of the measurements, the selected measurement, and the plan.

6. The method of claim 1, wherein adjusting the plan comprises:

determining whether the detected change may affect a series of products; and

determining whether to measure at least one of the products in the series of products based on the determination of whether the series of products may be affected.

7. The method of claim 6, wherein there is provided a plurality of products in a group, including the at least one product, and wherein the plan further comprises:

first information representative of the products in the group that are available to be measured; and

second information representative of the products in the group that are to be measured under the plan.

8. The method of claim 1, further comprising discarding information representative of measurement results on the at least one product when at least one of:

the measurement results indicate a variation in measurement of the at least one product, and a fault is detected in the manufacturing process.

9. The method of claim 1, wherein the plan comprises:

a plurality of splines radiating from a center of the at least one product, the candidate points being distributed along the splines; and

a distribution of the candidate points along the splines weighted according to a surface area of the at least one product.

10. A computer-implemented system of measuring at least one manufacturing characteristic for at least one product manufactured by a manufacturing process, comprising:

a memory to store information representative of a set of candidate points to be measured by the manufacturing process on the at least one product, and information representative of a plan for performing measurements on the at least one product to measure the at least one manufacturing characteristic, the plan defining the measurements to be made responsive to the set of candidate points; and

a processor, coupled to the memory, to

detect one of a plurality of events or a lack of one of the plurality of events indicating a change in the manufacturing process, the change pertaining to at least one of;

detecting a fault in the manufacturing process, and detecting a variation in a measurement of the at least one product;

determine whether to take more or fewer measurements based on the detected event or lack of the event; and

adjust the plan, in real time, to increase a spatial density of within-product measurements upon determining to take fewer measurements, and to decrease the spatial density of within-product measurements upon determining to take more measurements.

11. The system of claim 10, wherein the product to be measured is a semi-conductor wafer and the manufacturing process is an automated semi-conductor manufacturing process, further comprising at least one metrology tool for performing measurements on the semi-conductor wafer, operatively connected to the processor.

12. The system of claim 10, wherein the plan further comprises information representative of a metrology recipe.

13. The system of claim 10, wherein to adjust the plan comprises:

determining at least one region corresponding to the detected change;

selecting at least one measurement responsive to candidate points corresponding to the determined region;

assigning the selected at least one measurement as an additional measurement to be performed or as a measurement to be removed under the plan; and

revising at least one of the measurements, the selected measurement and the plan.

14. The system of claim 10, wherein to adjust the plan comprises:

determining whether the detected change may affect a series of products;

determining whether to measure at least one of the products in the series of products based on the determination of whether the series of products may be affected.

15. The system of claim 14, wherein there is provided a plurality of products in a group, including the at least one product, and wherein the plan further comprises:

first information representative of the products in the group that are available to be measured; and

second information representative of the products in the group that are to be measured under the plan.

16. The system of claim 10, wherein the memory is further to store information representative of measurement results on the at least one product, except when at least one of:

the measurement results indicate a variation in measurement of the at least one product, and when a fault is detected in the manufacturing process.

17. The system of claim 10, wherein the plan comprises:

a plurality of splines radiating from a center of the at least one product, the candidate points being distributed along the splines; and

a distribution of the candidate points along the splines is weighted according to a surface area of the at least one product.

18. A computer readable medium for measuring at least one manufacturing characteristic for at least one product manufactured by a manufacturing process, comprising executable instructions which when executed on a processing system cause the processing system to perform a method comprising:

providing information representative of a set of candidate points to be measured by the manufacturing process on the at least one product;

executing, by the manufacturing process, a plan for performing measurements on the at least one product to measure the at least one manufacturing characteristic, the plan defining the measurements to be made responsive to the set of candidate points, and the plan defining at least one region on the product, each of the candidate points corresponding to the at least one region;

detecting one of a plurality of events or a lack of one of the plurality of events indicating a change in the manufacturing process, the change pertaining to at least one of;

detecting a fault in the manufacturing process, and detecting a variation in a measurement of the at least one product;

determining whether to take more or fewer measurements due to the detected event or lack of the event; and

adjusting the plan, in real time, to increase a spatial density of within-product measurements upon determining to take fewer measurements, and to decrease the spatial density of within-product measurements upon determining to take more measurements.

19. The computer readable medium of claim 18, wherein adjusting the plan comprises:

determining at least one region corresponding to the detected change;

selecting at least one measurement responsive to candidate points corresponding to the determined region;

assigning the selected at least one measurement as an additional measurement to be performed or as a measurement to be removed under the plan; and

revising at least one of the measurements, the selected measurement, and the plan.

20. The computer readable medium of claim 18, wherein adjusting the plan comprises:

determining whether the detected change may affect a series of products; and

determining whether to measure at least one of the products in the series of products based on the determination of whether the series of products may be affected.

21. The computer readable medium of claim 18, further comprising instructions for discarding information representative of measurement results on the at least one product when at least one of:

the measurement results indicate a variation in measurement of the at least one product, and a fault is detected in the manufacturing process.

22. A computer-implemented system of measuring at least one manufacturing characteristic for at least one product manufactured by a manufacturing process, comprising:

means for representing a set of candidate points to be measured by the manufacturing process on the at least one product;

means for providing a plan for performing measurements on the at least one product to measure the at least one manufacturing characteristic, the plan defining the measurements to be made responsive to the set of candidate points, and the plan defining at least one region on the product, each of the candidate points corresponding to the at least one region;

means for detecting one of a plurality of events or a lack of one of the plurality of events indicating a change in the manufacturing process, the change pertaining to at least one of;

detecting a fault in the manufacturing process, and detecting a variation in a measurement of the at least one product;

means for determining whether to take more or fewer measurements based on the detected event or lack of the event; and

means for adjusting the plan, in real time, to increase a spatial density of within-product measurements upon determining to take fewer measurements, and to decrease the spatial density of within-product measurements upon determining to take more measurements.

23. The system of claim 22, wherein the means for adjusting the plan comprises:

determining at least one region corresponding to the detected change;

selecting at least one measurement responsive to the candidate points corresponding to the determined region;

assigning the selected at least one measurement as an additional measurement to be performed or as a measurement to be removed under the plan; and

revising at least one of the measurements, the selected measurement, and the plan.

24. The system of claim 22, wherein the means for adjusting the plan comprises:

determining whether the detected change may affect a series of products; and

determining whether to measure at least one of the products in the series of products based on the determination of whether the series of products may be affected.

25. The system of claim 22, further comprising means for representing measurement results on the at least one product, except when at least one of:

the measurement results indicate a variation in measurement of the at least one product, and a fault is detected in the manufacturing process.