Scatterometry for 0.24-0.70 um developed photoresist metrology

Michael R. Murnane; Christopher J. Raymond; Steven L. Prins; S. Sohail H. Naqvi; John Robert McNeil

doi:10.1117/12.209227

22 May 1995 Scatterometry for 0.24- to 0.70-μm developed photoresist metrology

Michael R. Murnane, Christopher J. Raymond, Steven L. Prins, S. Sohail H. Naqvi, John Robert McNeil

Proceedings Volume 2439, Integrated Circuit Metrology, Inspection, and Process Control IX; (1995) https://doi.org/10.1117/12.209227
Event: SPIE's 1995 Symposium on Microlithography, 1995, Santa Clara, CA, United States

Abstract

Scatterometry, the characterization of periodic structures via diffracted light analysis, is shown to be a viable and versatile metrology for critical dimensions as small as 0.24 micrometers . Scatterometry is rapid, nondestructive, inexpensive, and potentially useful for on- line control during several microlithographic processing steps. This paper discusses two recent studies in which scatterometry was applied to the measurement of developed photoresist patterns. First, scatterometric measurements of developed resist lines in the 0.38 micrometers to 0.70 micrometers range will be presented. Results from four sample wafers are shown to be consistent with SEM measurements. For one wafer, the average deviation of scatterometry linewidth measurements form top-down SEM measurements, over a broad exposure range, is 14.5 nm. Moreover, our scatterometer is shown to be highly linear with the SEM; linearity coefficients have typically been above 0.99. The goal of our second project has been to determine whether scatterometry measurements are affected by variations in the integrated circuit production process. A set of twenty-five wafers was fabricated with deliberate variations in the exposure dose and the underlying film thicknesses. We are presently investigating the effects of the film thicknesses on the measurements of critical dimensions (CDs) as small as 0.24 micrometers . Preliminary results indicate that CDs and multiple thin films can be simultaneously measured by applying multi-parameter prediction algorithms to the scattered light data. Results from four different prediction algorithms are given. Finally, the repeatability of the scatterometer is shown to be excellent: 0.5 nm for consecutive measurements and 0.8 nm for day-to-day measurements. The results of an extensive repeatability/precision experiment are presented.

Citation Download Citation

Michael R. Murnane, Christopher J. Raymond, Steven L. Prins, S. Sohail H. Naqvi, and John Robert McNeil "Scatterometry for 0.24- to 0.70-μm developed photoresist metrology", Proc. SPIE 2439, Integrated Circuit Metrology, Inspection, and Process Control IX, (22 May 1995); https://doi.org/10.1117/12.209227

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