Apparatus, method and program product for suppressing waviness of features to be printed using photolithographic systems

• US 20060010417A1
• Filed: 03/30/2005
• Published: 01/12/2006
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools B.V. (ASML Holding NV)
• Inventors: Laidig, Thomas, Eurlings, Markus Franciscus Antonius, Hollerbach, Uwe, Mulder, Melchior
• Granted Patent: US 7,856,606 B2
• Time in Patent Office: Days
• US Class Current: 716/52
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• CPC Class Codes: G03F 7/70433 Layout for increasing efficiency or for compensating imaging errors, e.g. layout of exposure fields for reducing focus errors; Use of mask features for increasing efficiency or for compensating imaging errors
• CPC Class Codes: G03F 7/70441 Optical proximity correction [OPC]
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions

Abstract

A method for minimizing rippling of features when imaged on a surface of a substrate using a mask. The method includes the steps of determining a deviation between a first representation of the design and a second representation of an image of the design at each of a plurality of evaluation points for each section of a plurality of sections of the design; determining an amount of modification of the design at each section based on an evaluation of the plurality of evaluation points; and modifying the design at each section by the amount determined in the previous step.

Claims

1. A method of optimizing a design to be formed on a substrate, comprising the steps of:

(a) determining a deviation between a first representation of the design and a second representation of an image of the design at each of a plurality of evaluation points for each section of a plurality of sections of the design;

(b) determining an amount of modification of the design at each section based on an evaluation of the plurality of evaluation points; and

(c) modifying the design at each section based on the amount determined step (b).

2. The method of optimizing the design, according to claim 1, further comprising the steps of:

(i) dividing the first representation of the design into the plurality of sections; and

(ii) dividing the second representation of the image of the design into a corresponding plurality of sections.

3. The method of optimizing the design, according to claim 1, further comprising the steps of:

(i) identifying a section type for each of the plurality of sections; and

(ii) determining whether each section type corresponds to a corner of the design.

4. The method of optimizing the design, according to claim 3, wherein when the section type corresponds to the corner, further comprising the step of not modifying the design at the section corresponding to the corner.

5. The method of optimizing the design, according to claim 3, wherein when the section type corresponds to the corner, further comprising the step of identifying whether the corner is a concave corner or a convex corner.

6. The method of optimizing the design, according to claim 5, wherein the corner is the concave corner, further comprising the steps of:

(i) determining a minimum deviation value from the plurality of evaluation points of the section; and

(ii) modifying the design at the section corresponding to the concave corner based on the minimum deviation value.

7. The method of optimizing the design, according to claim 5, wherein the corner is the convex corner, further comprising the steps of:

(i) determining a maximum deviation value from the plurality of evaluation points of the section; and

(ii) modifying the design at the section corresponding to the convex corner based on the maximum deviation value.

8. The method of optimizing the design, according to claim 1, further comprising the steps of:

(i) determining an evaluation method for each section of the plurality of sections according to each section type;

(ii) evaluating the deviation at each section based on the corresponding evaluation method identified in step (i);

(iii) modifying the design at each of the plurality of sections based on the results of step (ii).

9. The method of optimizing the design, according to claim 8, further comprising the step of identifying each section type of the plurality of sections.

10. The method of optimizing the design, according to claim 8, wherein each evaluation method is selected from a group consisting of minimum, maximum, middle, mean and median.

11. The method of optimizing the design, according to claim 1, for a given section of the plurality of sections, further comprising the steps of:

(i) determining the deviation at each of the evaluation points of the given section;

(ii) determining the deviation at each of a predetermined number of evaluation points of a section adjacent to the given section;

(iii) modifying the design at the given section based on an evaluation of the deviation at each of the evaluation points of step (i) and at each of the evaluation points of step (ii).

12. The method of optimizing the design, according to claim 11, further comprising the step of modifying the design at a corner section by an adjustment factor.

13. The method of optimizing the design, according to claim 1, for a given section, further comprising the steps of:

(i) evaluating the plurality of evaluation points of the given section by determining at least two deviation values comprising a first deviation value for the given section based on a first evaluation method and a second deviation value for the given section based on a second evaluation method;

(ii) determining a resulting deviation value based on the at least two deviation values; and

(iii) modifying the design at the given section based on a result of step (ii).

14. The method of optimizing the design, according to claim 13, wherein the first evaluation method is selected from a group consisting of minimum, maximum, middle, mean and median and the second evaluation method corresponds to a different method selected from the group.

15. The method of optimizing the design, according to claim 13, wherein the at least two deviation values further comprises a third deviation value for the given section based on a third evaluation method.

16. The method of optimizing the design, according to claim 15, wherein the first, second and third evaluation methods correspond to three methods selected from the group consisting of minimum, maximum, middle, mean and median.

17. The method of optimizing the design, according to claim 13, wherein step (ii) further comprises the step of determining the resulting deviation value by averaging the first deviation value and the second deviation value.

18. A computer program product, comprising executable code transportable by at least one machine readable medium, wherein execution of the code by at least one programmable computer causes the at least one programmable computer to perform a sequence of steps as in any one claims 1-17 for optimizing the design to be fabricated on the substrate.