Specular spectral profilometry on metal layers

Junwei Bao; Xinhui Niu; Nickhil H. Jakatdar; Costas J. Spanos; Joseph J. Bendik

doi:10.1117/12.386454

2 June 2000 Specular spectral profilometry on metal layers

Junwei Bao, Xinhui Niu, Nickhil H. Jakatdar, Costas J. Spanos, Joseph J. Bendik

Proceedings Volume 3998, Metrology, Inspection, and Process Control for Microlithography XIV; (2000) https://doi.org/10.1117/12.386454
Event: Microlithography 2000, 2000, Santa Clara, CA, United States

Abstract

With the advent of deep sub-micron semiconductor technology, metrology for metal interconnects becomes more critical. In addition to the line width, information about the height and the sidewall profile is needed to ensure good circuit performance. Conventional metrology tools such as CD SEMs and AFMs are either unable to measure the profile, or too slow for production process control. Scatterometry is a promising candidate as in situ, full-profile metrology tool. In this method, scattering of broadband light (240 nm to 760 nm) on periodical structures is simulated by approximating the structure with a finite series of Fourier expansion terms. By comparing the measured spectrum and the simulated spectra for various possible profiles in a precalculated library, the profile can be extracted. Previous work has shown good results on resist structures. For metal structures, however, more diffraction orders need to be included to accurately simulate light scattering. In this study, a library for 0.22 micrometer line and 0.44 micrometer space metal grating structures is generated using 31 orders. The profiles of metal grating structures of the same size are extracted using this library. Our data shows that the correlation between CD-SEM and scatterometry-based profile extraction appears to be related to the sidewall angle of the profile. These discrepancies will be analyzed and discussed.

Citation Download Citation

Junwei Bao, Xinhui Niu, Nickhil H. Jakatdar, Costas J. Spanos, and Joseph J. Bendik "Specular spectral profilometry on metal layers", Proc. SPIE 3998, Metrology, Inspection, and Process Control for Microlithography XIV, (2 June 2000); https://doi.org/10.1117/12.386454

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