A scatterometry based CD metrology solution for advanced nodes, including capability of handling birefringent layers with uniaxial anisotropy

Chih-Ming Ke; Jimmy Hu; Willie Wang; Jacky Huang; H. L. Chung; C. R. Liang; Victor Shih; H. H. Liu; H. J. Lee; John Lin; Y. D. Fan; Tony Yen; Noelle Wright; Ruben Alvarez Sanchez; Wim Coene; Marc Noot; Kiwi Yuan; Vivien Wang; Kaustuve Bhattacharyya; Karel van der Mast

doi:10.1117/12.814909

23 March 2009 A scatterometry based CD metrology solution for advanced nodes, including capability of handling birefringent layers with uniaxial anisotropy

Chih-Ming Ke, Jimmy Hu, Willie Wang, Jacky Huang, H. L. Chung, C. R. Liang, Victor Shih, H. H. Liu, H. J. Lee, John Lin, Y. D. Fan, Tony Yen, Noelle Wright, Ruben Alvarez Sanchez, Wim Coene, Marc Noot, Kiwi Yuan, Vivien Wang, Kaustuve Bhattacharyya, Karel van der Mast

Author Affiliations +

Proceedings Volume 7272, Metrology, Inspection, and Process Control for Microlithography XXIII; 72723R (2009) https://doi.org/10.1117/12.814909
Event: SPIE Advanced Lithography, 2009, San Jose, California, United States

Abstract

A brand new CD metrology technique that can address the need for accuracy, precision and speed in near future lithography is probably one of the most challenging items. CDSEMs have served this need for a long time, however, a change of or an addition to this traditional approach is inevitable as the increase in the need for better precision (tight CDU budget) and speed (driven by the demand for increase in sampling) continues to drive the need for advanced nodes. The success of CD measurement with scatterometry remains in the capability to model the resist grating, such as, CD and shape (side wall angle), as well as the under-lying layers (thickness and material property). Things are relatively easier for the cases with isotropic under-lying layers (that consists of single refractive or absorption indices). However, a real challenge to such a technique becomes evident when one or more of the under-lying layers are anisotropic. In this technical presentation the authors would like to evaluate such CD reconstruction technology, a new scatterometry based platform under development at ASML, which can handle bi-refringent non-patterned layers with uniaxial anisotropy in the underlying stack. In the RCWA code for the bi-refringent case, the elegant formalism of the enhanced transmittance matrix can still be used. In this paper, measurement methods and data will be discussed from several complex production stacks (layers). With inclusion of the bi-refringent modeling, the in-plane and perpendicular n and k values can be treated as floating parameters for the bi-refringent layer, so that very robust CD-reconstruction is achieved with low reconstruction residuals. As a function of position over the wafer, significant variations of the perpendicular n and k values are observed, with a typical radial fingerprint on the wafer, whereas the variations in the in-plane n and k values are seen to be considerably lower.

Citation Download Citation

Chih-Ming Ke, Jimmy Hu, Willie Wang, Jacky Huang, H. L. Chung, C. R. Liang, Victor Shih, H. H. Liu, H. J. Lee, John Lin, Y. D. Fan, Tony Yen, Noelle Wright, Ruben Alvarez Sanchez, Wim Coene, Marc Noot, Kiwi Yuan, Vivien Wang, Kaustuve Bhattacharyya, and Karel van der Mast "A scatterometry based CD metrology solution for advanced nodes, including capability of handling birefringent layers with uniaxial anisotropy", Proc. SPIE 7272, Metrology, Inspection, and Process Control for Microlithography XXIII, 72723R (23 March 2009); https://doi.org/10.1117/12.814909

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