Method for overlay error correction
The present disclosure provides a method for overlay error correction. The method includes: obtaining an overlay error based on a lower-layer pattern and an upper-layer pattern of a wafer, wherein the lower-layer pattern is obtained by first fabrication equipment through which the wafer passes, and the upper-layer pattern is obtained by exposure equipment; generating a corrected overlay error based on the overlay error and fabrication processes performed on the wafer after the first fabrication equipment and prior to the exposure equipment; and adjusting the exposure equipment based on the corrected overlay error.
1. A method for overlay error correction, comprising:
obtaining an overlay error based on a lower-layer pattern and an upper-layer pattern of a wafer, wherein the lower-layer pattern is obtained by first fabrication equipment through which the wafer passes, and the upper-layer pattern is obtained by exposure equipment;
generating a corrected overlay error based on the overlay error and fabrication processes perforated on the wafer after the first fabrication equipment and prior to the exposure equipment; and
adjusting the exposure equipment based on the corrected overlay error.
2. The method of claim 1 , wherein the lower-layer pattern comprises a plurality of first sub-patterns and a plurality of second sub-patterns, and a profile of each of the plurality of first sub-patterns is different from a profile of each of the plurality of second sub-patterns.
3. The method of claim 2 , wherein generating the corrected overlay error comprises:
classifying a plurality of correction parameters into a first group and a second group;
obtaining a first corresponding data of the first group of the plurality of correction parameters from the plurality of first sub-patterns, and a second corresponding data of the second group of the plurality of correction parameters from the plurality of second sub-patterns, respectively; and
generating the corrected overlay error based on the overlay error, the first corresponding data and the second corresponding data.
4. The method of claim 3 , further comprising:
obtaining a third corresponding data of the first group of the plurality of correction parameters from the plurality of second sub-patterns and a fourth corresponding data of the second group of the plurality of correction parameters from the plurality of second sub-patterns; and
selecting the first corresponding data and the second corresponding data to determine the corrected overlay error.
5. The method of claim 2 , wherein a pitch of the plurality of second sub-patterns is different from a pitch of the plurality of first sub-patterns.
6. The method of claim 2 , wherein in a plain view, each of the plurality of second sub-patterns extends along a third direction different from the first direction and the second direction.
7. The method of claim 2 , wherein each of the plurality of second sub-patterns comprises a plurality of segments arranged along the first direction.
8. The method of claim 2 , wherein in a plain view, a size of each of the plurality of second sub-patterns is different from a size of each of the plurality of first sub-patterns.
9. The method of claim 2 , wherein the number of the plurality of second sub-patterns is different from the number of the plurality of first sub-patterns.
10. The method of claim 1 , wherein the fabrication processes comprise at least one of an etching process, a deposition process, and a chemical mechanical polishing process.
11. The method of claim 1 , wherein adjusting the exposure equipment comprises adjusting a position of a reticle of the exposure equipment.
12. A method for overlay error correction, comprising:
receiving a wafer having a substrate;
forming a first pattern on the substrate of the wafer;
forming an intermediate structure covering the first pattern;
forming, by exposure equipment, a second pattern on the intermediate structure;
obtaining an overlay error based on the first pattern and the second pattern of the wafer;
generating a corrected overlay error based on the overlay error; and
adjusting the exposure equipment based on the corrected overlay error.
13. The method of claim 12 , wherein forming the first pattern comprises:
forming a plurality of first sub-patterns; and
forming a plurality of second sub-patterns, wherein a profile of each of the plurality of first sub-patterns is different from a profile of each of the plurality of second sub-patterns.
14. The method of claim 12 , wherein generating the corrected overlay error comprises:
classifying a plurality of correction parameters into a first group and a second group;
obtaining a first corresponding data of the first group of the plurality of correction parameters from the plurality of first sub-patterns and a second corresponding data of the second group of the plurality of correction parameters from the plurality of second sub-patterns, respectively; and
generating the corrected overlay error based on the overlay error, the first corresponding data and the second corresponding data.
15. The method of claim 14 , further comprising:
obtaining a third corresponding data of the first group of the plurality of correction parameters from the plurality of second sub-patterns and a fourth corresponding data of the second group of the plurality of correction parameters from the plurality of second sub-patterns; and
selecting the first corresponding data and the second corresponding data to determine the corrected overlay error.
16. The method of claim 13 , wherein in a plain view, each of the plurality of second sub-patterns extends along a third direction different from the first direction and the second direction, each of the plurality of second sub-patterns comprises a plurality of segments arranged along the first direction, and a pitch of the plurality of second sub-patterns is different from a pitch of the plurality of first sub-patterns.
17. The method of claim 13 , wherein in a plain view, a size of each of the plurality of second sub-patterns is different from a size of each of the plurality of first sub-patterns, and the number of the plurality of second sub-patterns is different from the number of the plurality of first sub-patterns.
18. The method of claim 12 , wherein the intermediate structure is formed by fabrication processes comprising at least one of an etching process, a deposition process, and a chemical mechanical polishing process.
19. The method of claim 12 , wherein adjusting the exposure equipment comprises adjusting a position of a reticle of the exposure equipment.