Automatic gate CD control for a full-chip-scale SRAM device

Chul-Hong Park; Tae Kyun Kim; Hoong-Joo Lee; Jeong-Taek Kong; Sang-Hoon Lee

doi:10.1117/12.301206

12 February 1997 Automatic gate CD control for a full-chip-scale SRAM device

Chul-Hong Park, Tae Kyun Kim, Hoong-Joo Lee, Jeong-Taek Kong, Sang-Hoon Lee

Proceedings Volume 3236, 17th Annual BACUS Symposium on Photomask Technology and Management; (1997) https://doi.org/10.1117/12.301206
Event: 17th Annual BACUS Photomask Technology and Management, 1997, Redwood City, CA, United States

Abstract

As the minimum feature size in VLSI circuits is reduced less than the wavelength of the exposure light, resolution enhancement technologies (RETs) have been developed. Optical proximity correction (OPC), which is one of RETs, can correct the difference in line width between isolate lines and lines in a dense array. Among the factors of CD variation (i.e., the optical proximity effect, numerical aperture, partial coherence, swing effect, and CD error on a mask), we have found that the optical proximity effect causes a severe isolate-dense bias larger than 35 nm. The optical proximity effect was corrected using an automatic tool based on an optical behavioral model. To determine the optimum threshold intensity, test patterns with the various threshold values were produced and measured using SEM. From this experiment, a proper threshold has been chosen and applied to a full chip pattern except the cell area in the gate layer of an SRAM device, which is optimized by photo engineer's experience. Furthermore, a model recipe correcting only the line width was set up to prevent the increase of the e-beam data size in two dimensional correction. Up to 40% reduction of CD variation can be expected, considering that more than 50% of gate layer patterns have the error distribution of -10 nm to 10 nm after OPC.

Citation Download Citation

Chul-Hong Park, Tae Kyun Kim, Hoong-Joo Lee, Jeong-Taek Kong, and Sang-Hoon Lee "Automatic gate CD control for a full-chip-scale SRAM device", Proc. SPIE 3236, 17th Annual BACUS Symposium on Photomask Technology and Management, (12 February 1997); https://doi.org/10.1117/12.301206

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