Alignment measurement method for imprint lithography using moiré fringe pattern

Jinyou Shao; Hongzhong Liu; Yucheng Ding; Li Wang; Bingheng Lu

doi:10.1117/1.3028350

1 November 2008 Alignment measurement method for imprint lithography using moiré fringe pattern

Jinyou Shao, Hongzhong Liu, Yucheng Ding, Li Wang, Bingheng Lu

Author Affiliations +

Optical Engineering, Vol. 47, Issue 11, 113604 (November 2008). https://doi.org/10.1117/1.3028350

Abstract

A simple and high-accuracy alignment measurement method based on a moiré fringe pattern is proposed. It involves relative rotation positioning and relative linear displacement measurement. Taking full advantage of the magnification effect of moiré fringe in angular and linear displacement, the relative rotation between the template and the wafer is determined first by measuring the inclination of the moiré fringe, and then the relative linear displacement between them is acquired by evaluating the spatial phase shift of two matched moiré fringes. The frequency components in the orthogonal directions of the fringe image obtained by a fast Fourier transform (FFT) and zooming process are used to measure the inclination of the moiré fringe. By selecting different orthogonal directions, a moiré fringe with any inclination can be measured accurately. When gratings are adjusted to parallel, a frequency-domain analysis is also used to extract the spatial phase of fringes at a given frequency. According to the relationship between spatial phase and linear displacement, the misalignment is detected. In experiments, the repeatability for the misalignment measurement has reached 4.8 nm (3).

©(2008) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Jinyou Shao, Hongzhong Liu, Yucheng Ding, Li Wang, and Bingheng Lu "Alignment measurement method for imprint lithography using moiré fringe pattern," Optical Engineering 47(11), 113604 (1 November 2008). https://doi.org/10.1117/1.3028350

Published: 1 November 2008

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