Accurate Pattern Registration for Integrated Circuit Tomography

Published

July 1, 2001

Author(s)

Zachary H. Levine, S Grantham, S Neogi, S P. Frigo, I McNulty, C C. Retsch, Y Wang, Thomas B. Lucatorto

Abstract

As part of an effort to develop high resolution microtomography for engineered structures, a two-level copper integrated circuit interconnect was imaged using 1.83 keV x-rays at 14 angles employing a full-field Fresnel zone plate microscope. A major requirement for high resolution microtomography is the accurate registration of the reference axes in each of the many views needed for a reconstruction. A reconstruction with 100 nm resolution would require registration accuracy of 30 nm or better. This work demonstrates that even images that have strong interference fringes can be used to obtain accurate fiducials through the use of Radon transforms. We show that we are able to locate the co-oridinates of the rectilinear circuit patterns to 28 nm. The procedure is validated by agreement between an x-ray parallax measurement of 1.41 0.7 m and a measurement of 1.58 0.08 m from an scanning electron microscope image of a cross section.

Citation

Journal of Applied Physics

Volume

90

Issue

No. 2

Pub Type

Journals

Keywords

Integrated circuit interconnect, metrology, parallax, tomography

Citation

Levine, Z. , Grantham, S. , Neogi, S. , Frigo, S. , McNulty, I. , Retsch, C. , Wang, Y. and Lucatorto, T. (2001), Accurate Pattern Registration for Integrated Circuit Tomography, Journal of Applied Physics (Accessed December 7, 2024)