System and method for field-by-field overlay process control using measured and estimated field parameters

Patent metadata

Field	Value
Publication number	US-10466596-B2
Application number	US-201414186744-A
Country	US
Kind code	B2
Filing date	Feb 21, 2014
Priority date	Feb 21, 2014
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The present disclosure is directed to a method of determining at least one correctable for a process tool. In an embodiment, the method includes the steps of: measuring one or more parameter values at one or more measurement locations of each field of a selection of measured fields of a wafer; estimating one or more parameter values for one or more locations of each field of a selection of unmeasured fields of the wafer; and determining at least one correctable for a process tool based upon the one or more parameter values measured at the one or more measurement locations of each field of the selection of measured fields of the wafer and the one or more parameter values estimated for the one or more locations of each field of the selection of unmeasured fields of the wafer.

First claim

What is claimed is:

1. A method, comprising:
measuring one or more parameter values at one or more measurement locations of each field of a first set of fields of a plurality of fields on a wafer with a metrology tool, wherein the first set of fields includes a fewer number of fields than the entire plurality of fields;
estimating one or more parameter values for one or more locations of each field of a second set of fields of the plurality of fields on the wafer via a first extrapolation mathematical model applied to a first subset of fields of the second set of fields of the plurality of fields and a second extrapolation mathematical model applied to a second subset of fields of the second set of fields of the plurality of fields, wherein the first extrapolation mathematical model is separate from the second extrapolation mathematical model, wherein the first subset of fields includes a fewer number of fields than the entirety of the second set of fields, wherein the second set of fields includes a fewer number of fields than the entire plurality of fields, wherein the first set of fields and the second set of fields include one or more different fields;
generating a first analysis map from the one or more parameter values measured at the one or more measurement locations of each field of the first set of fields of the plurality of fields on the wafer;
generating a second analysis map from the one or more parameter values estimated for the one or more locations of each field of the second set of fields of the plurality of fields on the wafer;
determining a plurality of correctables for a process tool based on the first analysis map and the second analysis map, wherein the one or more parameter values are estimated prior to the determining of the plurality of correctables, wherein the plurality of correctables includes at least one of one or more correctables for calibration of a semiconductor device production process or one or more correctables for calibration of the process tool; and
providing one or more control signals based on the plurality of correctables to the process tool to control at least one of a feed forward loop or a feedback loop during calibration of the process tool,
wherein the wafer is one of a first lot of wafers, wherein at least one of the feed forward loop or the feedback loop is configured to adjust the process tool during or prior to processing at least one wafer of a second lot of wafers.

2. The method of claim 1 , wherein at least one of the first extrapolation mathematical model or the second extrapolation mathematical model comprises a polynomial extrapolation.

3. The method of claim 1 , wherein at least one of the first extrapolation mathematical model or the second extrapolation mathematical model comprises a zonal extrapolation.

4. The method of claim 1 , wherein the first extrapolation mathematical model has a first assigned weight and the second extrapolation mathematical model has a second assigned weight.

5. The method of claim 1 , wherein the one or more parameter values measured at the one or more measurement locations of each field of a first subset of the first set of fields of the plurality of fields of the wafer are used as inputs for the first extrapolation mathematical model, and wherein the one or more parameter values measured at the one or more measurement locations of each field of a second subset of the first set of fields of the plurality of fields of the wafer are used as inputs for the second extrapolation mathematical model.

6. The method of claim 1 , wherein the one or more parameter values for the one or more locations of the first subset of fields of the second set of fields of the plurality of fields on the wafer are generated according to a first weighting of the first and second extrapolation mathematical models, wherein the one or more parameter values for the one or more locations of each field of the second subset of fields of the second set of fields of the plurality of fields on the wafer are generated according to a second weighting of the first and second extrapolation mathematical models.

7. The method of claim 1 , wherein the plurality of correctables comprises at least one optical adjustment for the process tool.

8. The method of claim 1 , wherein the plurality of correctables comprises at least one mechanical adjustment for the process tool.

9. The method of claim 1 , wherein the plurality of correctables comprises at least one of an APC run-to-run correction and a CPE field-by-field correction.

10. The method of claim 1 , further comprising:
measuring one or more parameter values at one or more measurement locations of a calibration wafer, wherein the plurality of correctables for the process tool are further based upon the one or more parameter values measured at the one or more measurement locations of the calibration wafer.

11. The method of claim 10 , wherein the plurality of correctables comprises at least one of an APC run-to-run correction, a CPE field-by-field correction, and a scanner baseline correction.

12. The method of claim 1 , further comprising:
generating a combined analysis map from the first analysis map and the second analysis map, wherein the plurality of correctables are determined from the combined analysis map, wherein the first analysis map is a two-dimensional visual representation of the measured one or more parameter values, wherein the second analysis map is a two-dimensional visual representation of the one or more parameter values estimated via the at least one mathematical model, wherein the combined analysis map is a combined two-dimensional visual representation.

13. The method of claim 1 , wherein the plurality of correctables includes one or more correctables for calibration of the semiconductor device production process and one or more correctables for calibration of the process tool.

14. A system comprising:
at least one metrology tool configured to measure one or more parameter values at one or more measurement locations of each field of a first set of fields of a plurality of fields on a wafer, wherein the first set of fields includes a fewer number of fields than the entire plurality of fields; and
at least one computing system configured to:
estimate one or more parameter values for one or more locations of each field of a second set of fields of the plurality of fields on the wafer via a first extrapolation mathematical model applied to a first subset of fields of the second set of fields of the plurality of fields and a second extrapolation mathematical model applied to a second subset of fields of the second set of fields of the plurality of fields, wherein the first extrapolation mathematical model is separate from the second extrapolation mathematical model, wherein the first subset of fields includes a fewer number of fields than the entirety of the second set of fields, wherein the second set of fields includes a fewer number of fields than the entire plurality of fields, wherein the first set of fields and the second set of fields include one or more different fields;
generate a first analysis map from the one or more parameter values measured at the one or more measurement locations of each field of the first set of fields of the plurality of fields on the wafer;
generate a second analysis map from the one or more parameter values estimated for the one or more locations of each field of the second set of fields of the plurality of fields on the wafer;
determine a plurality of correctables for a process tool based on the first analysis map and the second analysis map, wherein the one or more parameter values are est

Assignees

• Kla Tencor Corp

Inventors

• Pierson Bill
• Karur-Shanmugam Ramkumar
• Huang Chin-Chou
• Levy Ady
• Robinson John Charles

Classifications

• G03F7/705 Primary

  Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions · CPC title

• G03F7/70625

  Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness · CPC title

• G03F7/70633

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title

• G03F7/70483 Primary

  Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring · CPC title