The impact of mask birefringence on hyper-NA (NA>1.0) polarized imaging

Bernd Geh; Donis G. Flagello; Chris Progler; Patrick M. Martin; Leonardus H. A. Leunissen; Steve Hansen; Wim de Boeij

doi:10.1117/12.637483

4 November 2005 The impact of mask birefringence on hyper-NA (NA>1.0) polarized imaging

Bernd Geh, Donis G. Flagello, Chris Progler, Patrick M. Martin, Leonardus H. A. Leunissen, Steve Hansen, Wim de Boeij

Proceedings Volume 5992, 25th Annual BACUS Symposium on Photomask Technology; 599210 (2005) https://doi.org/10.1117/12.637483
Event: SPIE Photomask Technology, 2005, Monterey, California, United States

Abstract

The introduction of polarized light in high NA lithography requires additional characterization metrics for illumination systems. It has been shown that the percentage of the total light intensity that is polarized in the desired direction is a metric that can be closely related to wafer CD. On ASML systems, this quantity is called IPS (Intensity in Preferred State). Illuminators are characterized in terms of the minimum IPS found somewhere across the illuminated area and the IPS Range. In case the mask has a finite birefringence, there is an additional impact on the effective IPS. After passing through the mask blank, the IPS of the light will have changed and hence, there will be a response for wafer CD. Mask birefringence in conjunction with IPS introduces an additional contribution for the CD budget. This work will focus on the impact of mask birefringence on wafer CD for different scenarios of polarized illumination. We will show that the angle of the fast axis of birefringence can have a much greater impact on CD than the maximum birefringence magnitude itself. Based on these results we will derive a requirement for mask birefringence which has its foundation on CD. We will present measurements of the birefringence distributions of mask blanks, patterned masks, and masks with pellicles to investigate the contribution of the mask process flow starting from substrate, material deposition, processing, and final pellicle application. In addition to the material properties of the pellicle, the mounting of the pellicle to the substrate may induce additional stress birefringence.

Citation Download Citation

Bernd Geh, Donis G. Flagello, Chris Progler, Patrick M. Martin, Leonardus H. A. Leunissen, Steve Hansen, and Wim de Boeij "The impact of mask birefringence on hyper-NA (NA>1.0) polarized imaging", Proc. SPIE 5992, 25th Annual BACUS Symposium on Photomask Technology, 599210 (4 November 2005); https://doi.org/10.1117/12.637483

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