Computational metrology

1. A method for computational metrology, the method comprising:

obtaining a first distribution of a first parameter associated with a residual or error associated with a lithographic apparatus used in performing a device manufacturing process;

obtaining, from a metrology result, a second distribution of a second parameter associated with an error or residual in performing the device manufacturing process; and

determining, by a hardware computer, a distribution of a parameter of interest associated with the device manufacturing process based on combining the first and second distributions.

2. The method of claim 1 , wherein the first parameter, the second parameter and the parameter of interest are the same type of parameter.

3. The method of claim 1 , wherein the first distribution is specific to a particular substrate processed using the device manufacturing process but not generic to other substrates processed using the device manufacturing process.

4. The method of claim 1 , wherein the first distribution comprises one or more selected from: a contribution of a servo error to the first parameter, a contribution of an alignment model residual to the first parameter, a contribution of a projection system aberration or image plane deviation to the first parameter, a contribution of a projection system model residual to the first parameter, and/or a contribution of a substrate surface height to the first parameter.

5. The method of claim 1 , wherein the metrology result comprises focus metrology data and the first distribution comprises a contribution of a substrate surface height to the first parameter.

6. The method of claim 5 , wherein the focus metrology data is obtained by relatively sparse sampling of locations on a substrate and the distribution of the parameter of interest comprises a relatively dense spatial distribution of a focus parameter across the substrate.

7. The method of claim 1 , wherein the metrology result comprises critical dimension (CD) metrology data and the first distribution comprises a contribution of a substrate surface height to the first parameter.

8. The method of claim 7 , wherein the CD metrology data is obtained by relatively sparse sampling of locations on a substrate and the distribution of the parameter of interest comprises a relatively dense spatial distribution of a focus parameter across the substrate.

9. The method of claim 1 , wherein the metrology result comprises overlay metrology data.

10. The method of claim 9 , wherein the overlay metrology data is obtained by relatively sparse sampling of locations on a substrate and the distribution of the parameter of interest comprises a relatively dense spatial distribution of an overlay parameter across the substrate.

11. The method of claim 1 , further comprising using the distribution of the parameter of interest for predicting a hot spot on a substrate.

12. The method of claim 11 , wherein the hotspot is predicted based on at least a first parameter of interest being a CD and a second parameter of interest being an overlay parameter.

13. The method of claim 1 , further comprising predicting a shape and/or a size of one or more contours of a pattern using the distribution of the parameter of interest.

14. The method of claim 1 , wherein the first parameter and/or the second parameter is different than the parameter of interest and further comprising converting the first parameter and/or second parameter to the parameter of interest.

15. The method of claim 1 , wherein the first distribution is based on data from the lithographic apparatus and the second distribution is based on data from an inspection and/or metrology apparatus.

16. A computer program product comprising a non-transitory computer readable medium having instructions therein, wherein the instructions, when executed by a computer system, are configured to cause the computer system to at least:

obtain a first distribution of a first parameter associated with a residual or error associated with a lithographic apparatus used in performing a device manufacturing process;

obtain, from a metrology result, a second distribution of a second parameter associated with an error or residual in performing the device manufacturing process; and

determine a distribution of a parameter of interest associated with the device manufacturing process based on combining the first and second distributions.

17. The computer program product of claim 16 , wherein the metrology result comprises focus metrology data and the first distribution comprises a contribution of a substrate surface height to the first parameter.

18. The computer program product of claim 16 , wherein the metrology result comprises critical dimension metrology data and the first distribution comprises a contribution of a substrate surface height to the first parameter.

19. The computer program product of claim 16 , wherein the instructions are further configured to cause the computer system to predict a hot spot on a substrate using the distribution of the parameter of interest.

20. The computer program product of claim 19 , wherein the instructions configured to cause the computer system to predict the hotspot are configured to do so using at least two parameters of interest as input: a first parameter of interest being a critical dimension and a second parameter of interest being an overlay parameter.

21. The computer program product of claim 16 , wherein the instructions are further configured to cause the computer system to predict a shape and/or a size of one or more contours of a pattern using the distribution of the parameter of interest.

22. The computer program product of claim 16 , wherein the first parameter and/or the second parameter are different from the parameter of interest and wherein the instructions are further configured to cause the computer system to convert the first parameter and/or second parameter to the parameter of interest.