Improving the backend focus budget for 0.5 um lithography

Satyendra S. Sethi; Alex Flores; P. McHale; R. Booth; Steve W. Graca; S. Frezon; C. Fruga

doi:10.1117/12.209290

26 May 1995 Improving the backend focus budget for 0.5-um lithography

Satyendra S. Sethi, Alex Flores, P. McHale, R. Booth, Steve W. Graca, S. Frezon, C. Fruga

Proceedings Volume 2440, Optical/Laser Microlithography VIII; (1995) https://doi.org/10.1117/12.209290
Event: SPIE's 1995 Symposium on Microlithography, 1995, Santa Clara, CA, United States

Abstract

One of the biggest challenges for printing 0.6 micrometers metal lines (1.3 micrometers pitch) over 1.1 micrometers of topography is the shallow depth of focus. Total random errors, or, Built In Focus Errors (BIFE) for the class of steppers used in this study was determined to be 0.48 micrometers . When topography, and field curvature/astigmatism, are factored in, the required depth of focus to print the metal lines is approximately 2.18 micrometers . However, the 'Available' DOF (as determined from PROLITH simulations) is only 1.8 micrometers . The deficit between available DOF and required DOF grows bigger when there are multiple steppers. To overcome this deficiency, various techniques have been studied. Topography reduction by 0.4 micrometers was achieved by the use of Reverse Well technology. Effect of different resist chemistries, off-axis illumination, variation in numerical aperture and partial coherence, on the focus latitude are shown.

Citation Download Citation

Satyendra S. Sethi, Alex Flores, P. McHale, R. Booth, Steve W. Graca, S. Frezon, and C. Fruga "Improving the backend focus budget for 0.5-um lithography", Proc. SPIE 2440, Optical/Laser Microlithography VIII, (26 May 1995); https://doi.org/10.1117/12.209290

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