DETERMINATION METHOD, STORAGE MEDIUM AND INFORMATION PROCESSING APPARATUS

• US 20130010272A1
• Filed: 06/27/2012
• Published: 01/10/2013
• Est. Priority Date: 07/05/2011
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Gyoda, Yuichi, Mikami, Koji, Tsujita, Kouichirou
• Granted Patent: US 9,551,926 B2
• Time in Patent Office: Days
• US Class Current: 355/35
• CPC Class Codes: G03F 1/50 Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions

Abstract

The present invention provides a determination method of determining exposure conditions of an exposure apparatus including an illumination optical system which illuminates a mask, and a projection optical system which projects a pattern of the mask onto a substrate, the method including a step of setting an illumination parameter for a light intensity distribution formed on a pupil plane of the illumination optical system, and an aberration parameter for an aberration of the projection optical system, and a step of determining a value of the illumination parameter and a value of the aberration parameter so that an image performance of an optical image of the pattern of the mask satisfies an evaluation criterion set for a target pattern to be formed on an image plane of the projection optical system.

Claims

1. A determination method of determining exposure conditions of an exposure apparatus including an illumination optical system which illuminates a mask, and a projection optical system which projects a pattern of the mask onto a substrate, the method comprising:

a first step of setting an illumination parameter for a light intensity distribution formed on a pupil plane of the illumination optical system, and an aberration parameter for an aberration of the projection optical system; and

a second step of determining a value of the illumination parameter and a value of the aberration parameter so that an image performance of an optical image of the pattern of the mask, which is formed in an image plane of the projection optical system in correspondence with the pattern of the mask to be placed on an object plane of the projection optical system, satisfies an evaluation criterion set for a target pattern to be formed on the image plane of the projection optical system, thereby determining, as the exposure conditions, the light intensity distribution formed on the pupil plane of the illumination optical system and the aberration of the projection optical system, which are defined by the determined value of the illumination parameter and the determined value of the aberration parameter, respectively.

2. The method according to claim 1, wherein

in the first step, a mask parameter is set for the pattern of the mask to be placed on the object plane of the projection optical system, and

in the second step, a value of the mask parameter, a value of the illumination parameter, and a value of the aberration parameter are determined so that the image performance of the optical image of the pattern of the mask satisfies the evaluation criterion set for the target pattern to be formed on the image plane of the projection optical system, thereby determining, as the exposure conditions, the pattern of the mask, the light intensity distribution formed on the pupil plane of the illumination optical system, and the aberration of the projection optical system, which are defined by the determined value of the mask parameter, the determined value of the illumination parameter, and the determined value of the aberration parameter, respectively.

3. The method according to claim 1, wherein in the first step, a parameter representing an amount of aberration to be set in the projection optical system is set as the aberration parameter.

4. The method according to claim 1, wherein in the first step, a parameter representing an amount of aberration to be adjusted from an initial amount of aberration set in the projection optical system is set as the aberration parameter.

5. The method according to claim 1, wherein in the first step, a parameter representing an amount of driving of an optical element which forms the projection optical system is set as the aberration parameter.

6. The method according to claim 1, wherein the evaluation criterion includes at least one of a depth of focus on the image plane of the projection optical system, a difference between a dimension of the target pattern and a dimension of the optical image of the pattern of the mask, which is formed on the image plane of the projection optical system, and an exposure margin of the optical image of the pattern of the mask, which is formed on the image plane of the projection optical system.

7. The method according to claim 4, wherein the parameter representing the amount of aberration to be adjusted is expressed as a function of a distance from an optical axis of the projection optical system.

8. The method according to claim 1, further comprising a step of setting an evaluation position in the image plane of the projection optical system to evaluate the optical image of the pattern of the mask, which is formed on the image plane of the projection optical system,

wherein, in the second step, the value of the illumination parameter and the value of the aberration parameter are determined so that the image performance of the optical image of the pattern of the mask, which is formed at the evaluation position in correspondence with the pattern of the mask, satisfies the evaluation criterion.

10. An information processing apparatus executing a determination method defined in claim 1.

9. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a determination method of determining exposure conditions of an exposure apparatus including an illumination optical system which illuminates a mask, and a projection optical system which projects a pattern of the mask onto a substrate, the program causing the computer to execute:

a first step of setting an illumination parameter for a light intensity distribution formed on a pupil plane of the illumination optical system, and an aberration parameter for an aberration of the projection optical system; and

a second step of determining a value of the illumination parameter and a value of the aberration parameter so that an image performance of an optical image of the pattern of the mask, which is formed in an image plane of the projection optical system in correspondence with the pattern of the mask to be placed on an object plane of the projection optical system, satisfies an evaluation criterion set for a target pattern to be formed on the image plane of the projection optical system, thereby determining, as the exposure conditions, the light intensity distribution formed on the pupil plane of the illumination optical system and the aberration of the projection optical system, which are defined by the determined value of the illumination parameter and the determined value of the aberration parameter, respectively.