Cross-sectional gate feature identification method using top-down SEM images

Maki Tanaka; Chie Shishido; Yuji Takagi; Hidetoshi Morokuma; Osamu Komuro; Hiroyoshi Mori

doi:10.1117/12.483685

2 June 2003 Cross-sectional gate feature identification method using top-down SEM images

Maki Tanaka, Chie Shishido, Yuji Takagi, Hidetoshi Morokuma, Osamu Komuro, Hiroyoshi Mori

Proceedings Volume 5038, Metrology, Inspection, and Process Control for Microlithography XVII; (2003) https://doi.org/10.1117/12.483685
Event: Microlithography 2003, 2003, Santa Clara, California, United States

Abstract

This study presents a method of extracting 3D metrological information for etched gate structures from top-down SEM images for use in critical dimension analysis. The variations in sidewall angle and bottom corner roundness are quantified as feature indices by multiple parameter profile characterization (MPPC), and are used as the main indicators of device performance. A stable algorithm developed based on simulation and experimental results partitions the SEM image signal into the sidewall and footing based on the first derivative of the image signal. The width of the sidwall is used as an index of the sidewall angle, and the width of the footing is used as an index of the footing roundness. The validity of the MPPC method is confirmed through experiments using actual poly-Si gate wafers, and is shown to have a 3σ accuracy of ±0.9° for sidewall angles deviating by mroe than 2°. The sidewall angle index and its distribution map are useful for evaluating the etching process, and are particularly effective for revealing subtle macro variations like asymmetry, while the footing roundness index is useful for screening out bad wafers. As MPPC employs only top-down SEM images, no throughput loss will be incurred in comparison with conventional CD measurements.

Citation Download Citation

Maki Tanaka, Chie Shishido, Yuji Takagi, Hidetoshi Morokuma, Osamu Komuro, and Hiroyoshi Mori "Cross-sectional gate feature identification method using top-down SEM images", Proc. SPIE 5038, Metrology, Inspection, and Process Control for Microlithography XVII, (2 June 2003); https://doi.org/10.1117/12.483685

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