Approximate method of mask flatness factor in focus deviation

Shinroku Maejima; Seiichiro Shirai; Akira Imai; Shuji Nakao; Koji Tange; Akira Chiba; Kunihiro Hosono; Koichiro Narimatsu

doi:10.1117/12.681829

20 May 2006 Approximate method of mask flatness factor in focus deviation

Shinroku Maejima, Seiichiro Shirai, Akira Imai, Shuji Nakao, Koji Tange, Akira Chiba, Kunihiro Hosono, Koichiro Narimatsu

Author Affiliations +

Proceedings Volume 6283, Photomask and Next-Generation Lithography Mask Technology XIII; 62833A (2006) https://doi.org/10.1117/12.681829
Event: Photomask and Next Generation Lithography Mask Technology XIII, 2006, Yokohama, Japan

Abstract

Recent integrated circuit (IC) manufacturing processes require smaller critical dimension (CD) in order to facilitate the development of exposure tools with a higher numerical aperture (NA) and shorter wavelength. Consequently, the depth of focus (DOF) has considerably decreased, and the DOF currently required for 45-nm node devices is approximately 150 nm. Hence, the contribution of mask flatness to the total DOF increases. Inoue et al. systematically and precisely investigated the influence of mask flatness by using a free-standing plate and chucked plate interferometer. In this study, we fabricated several back side chrome (BSC) masks for focus monitoring, determined the flatness of these masks by an exposure experiment, and compared the flatness with that directly determined by using a free-standing plate interferometer. Thus, we verified the possibility of predicting the mask flatness component on an image plane by using the mask flatness data obtained using the interferometer.

Citation Download Citation

Shinroku Maejima, Seiichiro Shirai, Akira Imai, Shuji Nakao, Koji Tange, Akira Chiba, Kunihiro Hosono, and Koichiro Narimatsu "Approximate method of mask flatness factor in focus deviation", Proc. SPIE 6283, Photomask and Next-Generation Lithography Mask Technology XIII, 62833A (20 May 2006); https://doi.org/10.1117/12.681829

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