Material contrast based inline metrology: process verification and control using back scattered electron imaging on CD-SEM

Carsten Hartig; Daniel Fischer; Bernd Schulz; Alok Vaid; Ofer Adan; Shimon Levi; Adam Ge; Jessica Zhou; Maayan Bar-Zvi; Ronny Enge; Uwe Groh

doi:10.1117/12.2012011

10 April 2013 Material contrast based inline metrology: process verification and control using back scattered electron imaging on CD-SEM

Carsten Hartig, Daniel Fischer, Bernd Schulz, Alok Vaid, Ofer Adan, Shimon Levi, Adam Ge, Jessica Zhou, Maayan Bar-Zvi, Ronny Enge, Uwe Groh

Author Affiliations +

Proceedings Volume 8681, Metrology, Inspection, and Process Control for Microlithography XXVII; 868108 (2013) https://doi.org/10.1117/12.2012011
Event: SPIE Advanced Lithography, 2013, San Jose, California, United States

Abstract

The Critical Dimension Scanning Electron Microscope (CDSEM) is the traditional workhorse solution for inline process control. Measurements are extracted from top-down images based on secondary electron collection while scanning the specimen. Secondary electrons holding majority of detection yield. These images provide more on the structural information of the specimen surface and less in terms of material contrast. In some cases there is too much structural information in the image which can irritate the measurement, in other cases small but important differences between various material compounds cannot be detected as images are limited by contrast information and resolution of primary scanning beam. Furthermore, accuracy in secondary electron based metrology is limited by charging. To gather the exact required information for certain material compound as needed, a technique, known from material analytic SEM´s has been introduced for inline CDSEM analysis and process control: Low Loss Back Scattered Electron Imaging (LL-BSE). The key at LL-BSE imaging is the collection of only the back scattered electrons (BSE) from outermost specimen surface which undergo the least amount possible of energy loss in the process of image generation following impact of the material by a primary beam. In LL-BSE very good and measurable material distinction and sensitivity, even for very low density material compounds can be achieved. This paper presents new methods for faster process development cycle, at reduced cost, based on LL-BSE mass data mining instead of sending wafers for destructive material analysis.

Citation Download Citation

Carsten Hartig, Daniel Fischer, Bernd Schulz, Alok Vaid, Ofer Adan, Shimon Levi, Adam Ge, Jessica Zhou, Maayan Bar-Zvi, Ronny Enge, and Uwe Groh "Material contrast based inline metrology: process verification and control using back scattered electron imaging on CD-SEM", Proc. SPIE 8681, Metrology, Inspection, and Process Control for Microlithography XXVII, 868108 (10 April 2013); https://doi.org/10.1117/12.2012011

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