Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-06T13:04:35.271Z Has data issue: false hasContentIssue false
  • English
  • Français

Assessment of Planarization length variation by the Step-Polish-Response (SPR) Method

Published online by Cambridge University Press:  15 March 2011

Johann. W. Bartha ,
Tilo Bormann ,
Kathrin Estel  and
Dieter Zeidler
Johann. W. Bartha
Affiliation:
Dresden Universityof Technology, Institute of Semiconductor and Microsystems Technology 01062 Dresden, Germany
Tilo Bormann
Affiliation:
Dresden Universityof Technology, Institute of Semiconductor and Microsystems Technology 01062 Dresden, Germany
Kathrin Estel
Affiliation:
Dresden Universityof Technology, Institute of Semiconductor and Microsystems Technology 01062 Dresden, Germany
Dieter Zeidler
Affiliation:
Dresden Universityof Technology, Institute of Semiconductor and Microsystems Technology 01062 Dresden, Germany
Get access

Abstract

In spite of the fact, that the main purpose of CMP is the planarization of surfaces, most processes are optimized with respect to the removal rate. This might be due to a lack in techniques for the determination of the planarization behavior. The commonly used expression “Planarization Length” implies a maximum lateral extension over which the planarization is obtained and which can not be improved. Several attempts have been made to determine the planarization length by studying the CMP on different test patterns. The general problem in the interpretation of the data is the interaction of neighboring pattern with different pattern densities. This problem does not apply to the most simple pattern possible, which is a single step with an extension of the up and down areas much larger than the planarization length. In this case the spatial derivative of the resulting contour after CMP is directly the demanding transfer function to be used for the convolution. This concept, initially proposed by Boning et. al., was applied to evaluate the polish of copper and silicon oxide. Wafers with concentrically steps in Cu or SiO2 films with an extension of 1 to 5 cm have been prepared. During polish, the initially infinite steep step widens up, yielding the planarization length as a function of the removal respective the polishing time. Significant differences in the evaluation of the planarization length could be quantified depending on the pad, slurry and tool parameters. Our first experiments revealed a decrease in planarization length by the addition of BTA in a copper slurry. We believe that the SPR method enables a unambiguous, pattern independent determination of the planarization capability in CMP.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 816: Symposium K – Advances in Chemical-Mechanical Polishing , 2004 , K8.5
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Boning, Duane, Lee, Brian, Baylies, W., Poduje, N., Hester, P., Valley, J., Koliopoulos, C., Hetherington, D., “Characterization and Modeling of Nanotopography Effects on CMP”, International CMP Symposium 2000, Tokyo, Japan, (2000)Google Scholar
2. Lefevre, P., Gonzales, A., Brown, T., Martin, G., Tugbawa, T., Park, T., Boning, D., Gostein, M., Nguyen, J., J., , “Direct Measurement of Planarization Length for Copper Chemical Mechanical Polishing (CMP) Processes using a large Pattern Test Mask”, MRS 2001 (2001)Google Scholar
3. Boning, Duane, Chung, James, Ouma, Dennis, and Divecha, Rajesh “Spatial Variations in Semiconductor Processes: Modelling for Control”, ECS Meeting, Montreal, May, 1997 Google Scholar
4. Zeidler, D., Bartha, J. W., Lortz, W., Brandes, R., “Modified Abrasives based on fumed SiO2 and Al2O3 for the Cu CMP Process”, Proc. of the MRS Spring Meeting, Apr. 12-16, 2004, San Francisco Google Scholar