System and method for imaging enhancement via calculation of a customized optimal pupil field and illumination mode

• US 20060170617A1
• Filed: 01/31/2005
• Published: 08/03/2006
• Est. Priority Date: 01/31/2005
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Latypov, Azat M., Cebuhar, Wenceslao A., Hintersteiner, Jason D.
• Granted Patent: US 7,542,013 B2
• Time in Patent Office: Days
• US Class Current: 345/32
• CPC Class Codes: G03F 7/70116 Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets

Abstract

A system and method for patterning a beam of radiation based on a pupil field distribution. In an embodiment, the distribution of the field in an area of the pupil plane affecting an image and an illumination mode are selected so as to render an image with desired characteristics. Additionally and/or alternatively, an illumination mode is selected so as to render an image with desired characteristics. The distribution of the field in an area of the pupil plane affecting an image is then realized using the spatial light modulator The system and method include using an illumination system, a pattern generator, and a projector. The illumination system supplies a beam of radiation. The pattern generator patterns the beam of radiation based on a data set corresponding to a field distribution in a pupil plane. The projector projects the patterned beam onto a target portion of an object.

Claims

1. A method, comprising:

(a) receiving a data set based on a field distribution in a pupil plane corresponding to an image;

(b) modifying the data set to result in a modified data set that represents a desired field distribution in the pupil plane, the desired field distribution corresponding to the image having desired characteristics;

(c) transforming the modified data set into states of pixels located on a dynamic pattern generator;

(d) setting the states of the pixels of the dynamic pattern generator according to the states determined in step (c);

(e) patterning a beam of radiation with the dynamic pattern generator; and

(f) projecting the patterned beam onto a target portion of a substrate.

2. The method of claim 1, wherein step (b) comprises:

selecting an illumination mode of an extended source optically conjugate to the field distribution, such that the modification of the data set in step (b) results in the desired field distribution in the pupil plane.

3. The method of claim 2, wherein step (b) further comprises:

using at least one of a conventional, an annular, a quasar, a dipole, a quadrapole, a hexapole, an octapole, a polarized, an unpolarized, an on-axis and an off-axis mode as the illumination mode.

4. The method of claim 1, wherein step (b) comprises:

using at least one of placement of features, image log slope, critical dimension uniformity, contrast of image and out-of-focus behavior as the desired characteristics of the image.

5. The method of claim 1, wherein step (a) comprises:

calculating an inverse Fourier Transform of an image field corresponding to a desired image in the image plane; and

using the calculation of the inverse Fourier Transform as the data set.

6. The method of claim 1, wherein step (b) comprises:

(i) computing from the data set received in step (a) the image that corresponds to the field distribution in the pupil plane;

(ii) determining if there are discrepancies between characteristics of the image and the desired characteristics; and

(iii) iteratively modifying the data set to minimize the discrepancies, thereby resulting in the modified data set.

7. The method of claim 1, wherein step (b) comprises:

modifying the data set so that the modified data set accounts for at least one of optical proximity effects and optical proximity correction features in the pupil field distribution.

8. The method of claim 1, wherein step (e) comprises:

using at least one of tilting reflective devices, pistoning reflective devices, graytoning transmissive devices and graytoning reflective devices in the dynamic pattern generator.

9. The method of claim 1, wherein step (f) comprises:

using one of a wafer, a projection system display device and a projection television display device as the substrate.

10. The method of claim 1, further comprising:

using at least one of an aerial image and an image in a layer of photoresist disposed on the substrate as the image.

11. The method of claim 1, wherein step (a) comprises:

using imaging characteristics of one of a binary mask pattern, attenuated phase-shift mask pattern, an alternating phase-shift mask pattern, or a multi-phase mask pattern as a basis for the data set.

12. The method of claim 1, wherein step (a) comprises:

using the desired characteristics at the substrate as a basis for the data set.

13. A system for patterning a beam of radiation, comprising:

an illumination system that supplies the beam of radiation;

a pattern generator that patterns the beam of radiation based on a data set corresponding to a desired field distribution in a pupil plane; and

a projector that projects the patterned beam onto a target portion of a substrate.

14. The system of claim 13, further comprising:

an image controller that transforms the data set into states of pixels located on the pattern generator.

15. The system of claim 14, wherein:

the image controller determines an illumination mode of an extended source optically conjugate to the pupil plane, such that the data set results in the desired field distribution in the pupil plane.

16. The system of claim 15, wherein the illumination mode comprises at least one of a conventional, an annular, a quasar, a dipole, a quadrapole, a hexapole, an octapole, a polarized, an unpolarized, an on-axis and an off-axis mode.

17. The system of claim 13, wherein the desired field distribution corresponds with an image at an image plane having at least one of placement of features, image log slope, critical dimension uniformity, image contrast and out-of-focus behavior.

18. The system of claim 13, wherein the data set comprises an inverse Fourier Transform of an image.

19. The system of claim 13, wherein the pattern generator comprises at least one of tilting reflective devices, pistoning reflective devices, graytoning transmissive devices and graytoning reflective devices.

20. The system of claim 13, wherein the substrate comprises one of a wafer, a projection system display device, and a projection television system display device.