Sensitivity of SEM width measurements to model assumptions

J. S. Villarrubia; Z. J. Ding

doi:10.1117/12.814300

23 March 2009 Sensitivity of SEM width measurements to model assumptions

J. S. Villarrubia, Z. J. Ding

Proceedings Volume 7272, Metrology, Inspection, and Process Control for Microlithography XXIII; 72720R (2009) https://doi.org/10.1117/12.814300
Event: SPIE Advanced Lithography, 2009, San Jose, California, United States

Abstract

The most accurate width measurements in a scanning electron microscope (SEM) require raw images to be corrected for instrumental artifacts. Corrections are based upon a physical model that describes the sample-instrument interaction. Models differ in their approaches or approximations in the treatment of scattering cross sections, secondary electron (SE) generation, material properties, scattering at the surface potential barrier, etc. Corrections that use different models produce different width estimates. We have implemented eight models in the JMONSEL SEM simulator. Two are phenomenological models based upon fitting measured yield vs. energy curves. Two are based upon a binary scattering model. Four are variants of a dielectric function approach. These models are compared to each other in pairwise simulations in which the output of one model is fit to the other by using adjustable parameters similar to those used to fit measured data. The differences in their edge position parameters is then a measure of how much these models differ with respect to a width measurement. With electron landing energy, beam width, and other parameters typical of those used in industrial critical dimension measurements, the models agreed to within ±2.0 nm on silicon and ±2.6 nm on copper in 95% of comparisons.

Citation Download Citation

J. S. Villarrubia and Z. J. Ding "Sensitivity of SEM width measurements to model assumptions", Proc. SPIE 7272, Metrology, Inspection, and Process Control for Microlithography XXIII, 72720R (23 March 2009); https://doi.org/10.1117/12.814300

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