Evaluation method, determination method, lithography apparatus, and non-transitory computer-readable storage medium

1. An evaluation method of evaluating a measurement condition of a position of a mark formed on a substrate, the method comprising:

obtaining a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under the measurement condition;

generating a plurality of evaluation signals combining a plurality of first pseudo components with a first signal corresponding to the mark signal with a first frequency component removed therefrom, the plurality of first pseudo components being created by using different values of a first parameter of the first frequency component; and

estimating positions of the mark from the plurality of generated evaluation signals, and obtaining a variation in the estimated positions of the mark as an evaluation index of the measurement condition.

2. The method according to claim 1 , wherein the generating, removes the first frequency component, which is a low-frequency component, from the mark signal using a low-pass filter.

3. The method according to claim 1 , wherein;

the mark includes a line and space pattern formed from a plurality of line elements, and

the first signal frequency component includes a noise component caused by a difference in intensity of reflected light between the plurality of line elements.

4. The method according to claim 1 , wherein the generating creates the plurality of first pseudo components by changing a phase of the first frequency component as the first parameter of the first frequency component.

5. The method according to claim 1 , wherein;

the generating generates the plurality of evaluation signals by further combining a plurality of second pseudo components with a second signal corresponding to the mark signal with a second frequency component removed therefrom, the plurality of second pseudo components being created by using different values for a second parameter of the second frequency component, and

a frequency of the second frequency component is higher than a frequency of the first frequency component.

6. The method according to claim 5 , wherein the generating removes the second frequency component, which is a high-frequency component, from the mark signal using a high-pass filter.

7. The method according to claim 5 , wherein the second frequency component is a white noise component removed from the mark signal.

8. The method according to claim 5 , wherein the generating creates the plurality of second pseudo components by changing the second parameter of the second frequency component without changing amplitudes of the plurality of second pseudo components from an amplitude of the second frequency component.

9. A determination method of determining a measurement condition of a position of a mark formed on a substrate, the determination method comprising:

setting a plurality of candidate conditions concerning the measurement condition;

obtaining an evaluation index for each of the plurality of candidate conditions by an evaluation method; and

determining the measurement condition based on the evaluation index obtained for each of the plurality of candidate conditions,

wherein the evaluation method comprises:

obtaining a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under one candidate condition among the plurality of candidate conditions;

generating a plurality of evaluation signals by combining a plurality of pseudo components with a signal corresponding to the mark signal with frequency component removed therefrom, the plurality of pseudo components being created by setting different values for a parameter of the frequency component; and

estimating positions of the mark from the plurality of generated evaluation signals, and obtaining a variation in the estimated positions of the mark as the evaluation index of the respective candidate condition.

10. A lithography apparatus for forming a pattern on a substrate, the apparatus comprising:

a measurement unit configured to measure a position of a mark formed on the substrate; and

a processing unit configured to determine a measurement condition of the position of the mark to be used by the measurement unit, wherein the processing unit:

sets a plurality of candidate conditions concerning the measurement condition;

obtains an evaluation index for each of the plurality of candidate conditions; and

determines the measurement condition based on the evaluation index obtained for each of the plurality of candidate conditions,

wherein the processing unit, in obtaining the evaluation index for each of the plurality of candidate conditions:

obtains a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under one candidate condition among the plurality of candidate conditions;

generates a plurality of evaluation signals by combining a plurality of pseudo components with a signal corresponding to the mark signal with a frequency component removed therefrom, the plurality of pseudo components being created by setting different values for a parameter of the frequency component; and

respectively estimates positions of the mark from the plurality of generated evaluation signals, and obtains a variation in the estimated positions of the mark as the evaluation index of the respective candidate condition.

11. A non-transitory computer-readable storage medium storing a program executable by a computer to execute an evaluation method of evaluating a measurement condition of a position of a mark formed on a substrate, the evaluation method comprising:

obtaining a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under the measurement condition;

generating a plurality of evaluation signals by respectively combining a plurality of pseudo components with a signal corresponding to the mark signal with frequency component removed therefrom, the plurality of pseudo components being created by setting different values for a parameter of the frequency component; and

estimating positions of the mark from the plurality of generated evaluation signals, and obtaining a variation in the estimated positions of the mark as an evaluation index of the measurement condition.

12. A non-transitory computer-readable storage medium storing a program executable by a computer to execute a determination method of determining a measurement condition of a position of a mark formed on a substrate, the method comprising:

setting a plurality of candidate conditions concerning the measurement condition;

obtaining an evaluation index for each of the plurality of candidate conditions by an evaluation method; and

determining the measurement condition based on the evaluation index obtained for each of the plurality of candidate conditions,

wherein the evaluation method comprises:

obtaining a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under one candidate condition among the plurality of candidate conditions;

generating a plurality of evaluation signals by combining a plurality of pseudo components with a signal corresponding to the mark signal with frequency component removed therefrom, the plurality of pseudo components being created by setting different values for a parameter of the frequency component; and

estimating positions of the mark from the plurality of generated evaluation signals, and obtaining a variation in the estimated positions of the mark as the evaluation index of the respective candidate condition.

13. A method of manufacturing an article, the method comprising:

setting a plurality of candidate conditions concerning a measurement condition of a position of a mark formed on a substrate;

obtaining an evaluation index for each of the plurality of candidate conditions by an evaluation method;

determining the measurement condition based on the evaluation index obtained for each of the plurality of candidate conditions;

measuring the position of the mark under the determined measurement condition; exposing the substrate based on a result of the measuring of the position of the mark; processing the exposed substrate; and manufacturing an article from the processed substrate,

wherein the evaluation method comprises:

obtaining a mark signal representing an intensity distribution of reflected light by detecting the reflected light from the mark under one candidate condition among the plurality of candidate conditions;

generating a plurality of evaluation signals by combining a plurality of pseudo components with a signal corresponding to the mark signal with a frequency component removed therefrom, the plurality of pseudo components being created by setting different values for a parameter of the frequency component; and

estimating positions of the mark from the plurality of generated evaluation signals, and obtaining a variation in the estimated positions of the mark as the evaluation index of the respective candidate condition.