Improvement of alignment accuracy for scaled exposure field

Satoshi Nakajima; Makoto Tanigawa; Akira Ishihama; Keizo Sakiyama

doi:10.1117/12.275964

7 July 1997 Improvement of alignment accuracy for scaled exposure field

Satoshi Nakajima, Makoto Tanigawa, Akira Ishihama, Keizo Sakiyama

Proceedings Volume 3050, Metrology, Inspection, and Process Control for Microlithography XI; (1997) https://doi.org/10.1117/12.275964
Event: Microlithography '97, 1997, Santa Clara, CA, United States

Abstract

As the reduction of design rules, improvement of the overlay accuracy for intra exposure field comes to b important. We traced the transition of the exposure field size for each process steps, and found that the LOCOS oxidation has fairly large effect on the expansion of exposure field. For the range of 400-1000nm of LOCOS oxidation thickness, the expansion ratio was about 3.8-4.2 ppm. This expansion ratio is proportional to the oxidation thickness within that range. At the length of a side of 20mm exposure field, this value is equal to 0.08micrometers . So the overlay error at the corners of exposure field is amount to 0.04micrometers . This amount is not negligible for the quarter micron design rule. For the purpose of improving the overlay accuracy for extended field which is caused by LOCOS oxidation, we investigated the method of reducing the projective magnification for the isolation layer. The overlay accuracy with the reduction of -3 ppm shows the 0.065 micrometers as the 3 sigma value, and is improved to the half of control wafer with the reduction of 0 ppm.

Citation Download Citation

Satoshi Nakajima, Makoto Tanigawa, Akira Ishihama, and Keizo Sakiyama "Improvement of alignment accuracy for scaled exposure field", Proc. SPIE 3050, Metrology, Inspection, and Process Control for Microlithography XI, (7 July 1997); https://doi.org/10.1117/12.275964

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