Exposure monitor structure

Alexander Starikov

doi:10.1117/12.20057

1 June 1990 Exposure monitor structure

Alexander Starikov

Proceedings Volume 1261, Integrated Circuit Metrology, Inspection, and Process Control IV; (1990) https://doi.org/10.1117/12.20057
Event: Microlithography '90, 1990, San Jose, CA, United States

Abstract

A novel exposure monitor structure (EMS) is proposed as a sensitive means to monitor or measure effective exposure dose in the optical lithographic printing. Like windows of graduated transmittance, it is very sensitive to dose, but not to focus. On the other hand, EMS is compact to allow placement in the kerf or device layouts and it is measurable by automated rctetrology tools. EMS is built in the conventional reticles by arranging a set of stripes of chrome and glass on the period near MTF cut-off in a manner simulating transmission wedges on both sides of a conventional line. Since the fine structure of EMS is not resolved by the optical lithography tool used for printing, it performs like a transmission wedge. Conventional linewidth measurements of a printed EMS image are used to monitor exposure dose. Coupled with a calibration curve, sensitive dose measurements can also be made. Modelling of printing of EMS and of a conventional line on an optical stepper indicates that printed linewidth of EMS changes much faster as the function of dose. EMS also displays relatively little sensitivity to defocus. Conventional 5X reticles with EMS were built. Exposure sequences were carried out on a G-line stepper. Linewidth measurements of printed EMS and of conventional lines were done on a typical linewidth measurement tool. Experiment confirms that linewidth of printed EMS is much more sensitive to dose than that of a conventional line. Once linewidth of EMS is established at the desirable dose, EMS may be used to set that dose in the subsequent runs. With more accurate dose set-up and job disposition decisions, higher product tolerance can be achieved with existing equipment and process.

Citation Download Citation

Alexander Starikov "Exposure monitor structure", Proc. SPIE 1261, Integrated Circuit Metrology, Inspection, and Process Control IV, (1 June 1990); https://doi.org/10.1117/12.20057

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