Strategies for nanoscale contour metrology using critical dimension atomic force microscopy

Ndubuisi G. Orji; Ronald G. Dixson; András E. Vládar; Michael T. Postek

doi:10.1117/12.894416

20 September 2011 Strategies for nanoscale contour metrology using critical dimension atomic force microscopy

Ndubuisi G. Orji, Ronald G. Dixson, András E. Vládar, Michael T. Postek

Proceedings Volume 8105, Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors V; 810505 (2011) https://doi.org/10.1117/12.894416
Event: SPIE NanoScience + Engineering, 2011, San Diego, California, United States

Abstract

Contour metrology is one of the techniques used to verify optical proximity correction (OPC) in lithography models. These methods, known as resolution enhancement techniques (RET), are necessary to continue the decrease in integrated circuit feature sizes. Broadly speaking, RET are used to compensate for lithography errors to ensure better image transfer from the mask to the wafer and subsequence processing. Contours extracted from the printed features are used to verify the OPC models. Currently, the scanning electron microscope (SEM) is used to generate and verify the contours. The critical dimension atomic force microscope (CD-AFM), which is being used as a reference instrument in lithography metrology, has been proposed as a supplemental instrument for contour verification. This is mostly due to the relative insensitivity of the CD-AFM to material properties, the three-dimensional data, and the ability to make the instrument traceable to the SI unit of length. However, although the data from the CD-AFM is inherently three dimensional, the planar two-dimensional data required for contour metrology is not easily compared with the top-down AFM data. This is mostly due to the effect of the CDAFM tip and the scanning strategy. In this paper we outline some of the methods for acquiring contour data using the CD-AFM. Specifically, we look at different scanning strategies, tip types, contour extraction methods, and imaging modes. We compare contours extracted using our method to those acquired using the SEM.

Citation Download Citation

Ndubuisi G. Orji, Ronald G. Dixson, András E. Vládar, and Michael T. Postek "Strategies for nanoscale contour metrology using critical dimension atomic force microscopy", Proc. SPIE 8105, Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors V, 810505 (20 September 2011); https://doi.org/10.1117/12.894416

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