In-situ aberration monitoring using phase wheel targets

Lena V. Zavyalova; Bruce W. Smith; Toshifumi Suganaga; Seiji Matsuura; Toshiro Itani; Julian S. Cashmore

doi:10.1117/12.537379

28 May 2004 In-situ aberration monitoring using phase wheel targets

Lena V. Zavyalova, Bruce W. Smith, Toshifumi Suganaga, Seiji Matsuura, Toshiro Itani, Julian S. Cashmore

Proceedings Volume 5377, Optical Microlithography XVII; (2004) https://doi.org/10.1117/12.537379
Event: Microlithography 2004, 2004, Santa Clara, California, United States

Abstract

Aberration metrology is critical to the manufacture of quality lithography lenses in order to meet strict optical requirements. Additionally, it is becoming increasingly important to be able to measure and monitor lens performance in an IC production environment on a regular basis. The lithographer needs to understand the influence of aberrations on imaging and any changes that may occur in the aberration performance of the lens between assembly and application, and over the course of using an exposure tool. This paper will present a new method for the detection of lens aberrations that may be employed during standard lithography operation. The approach allows for the detection of specific aberration types and trends, as well as levels of aberration, though visual inspection of high resolution images of resist patterns and fitting of the aberrated wavefront. The approach consists of a test target made up of a 180-degree phase pattern array in a “phase wheel” configuration. The circular phase regions in the phase wheel are arranged so that their response to lens aberration is interrelated and the regions respond uniquely to specific aberrations, depending on their location within the target. This test method offers an advantage because of the sensitivity to particular aberration types, the unique response of multiple zones of the test target to aberrations, and the ease with which aberrations can be distinguished. The method of lens aberration detection is based on the identification of the deviations that occur between the images printed with the phase wheel target and images that would be produced in the absence of aberration. This is carried out through the use of lithography simulation, where simulated images can be produced without aberration and with various levels of lens aberration. Comparisons of printed resist images to simulated resist images are made while the values of the coefficients for the primary Zernike aberrations are varied.

Citation Download Citation

Lena V. Zavyalova, Bruce W. Smith, Toshifumi Suganaga, Seiji Matsuura, Toshiro Itani, and Julian S. Cashmore "In-situ aberration monitoring using phase wheel targets", Proc. SPIE 5377, Optical Microlithography XVII, (28 May 2004); https://doi.org/10.1117/12.537379

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available