Implementation of a Reference Measurement System Using CD-AFM

Published

May 1, 2003

Author(s)

Ronald G. Dixson, Theodore V. Vorburger, Angela Guerry, Marylyn H. Bennett, B Bunday

Abstract

International SEMATECH (ISMT) and the National Institute of Standards and Technology (NIST) are working together to improve the traceability of atomic force microscope (AFM) dimensional metrology in semiconductor manufacturing. The rapid pace of technological change in the semiconductor industry makes the timely introduction of relevant standards challenging. As a result, the link between the realization of the SI (Systeme International d'Unites, or International System of Units) unit of length - the meter - and measurements on the fab line is not always maintained. To improve this situation, we are using an at-line critical dimension-AFM (CD-AFM) at ISMT as a developmental platform. This tool has been implemented as a Reference Measurement System (RMS) in the facilities at ISMT. However, it is currently being replaced by a next-generation CD-AFM tool. Using the current tool, we have performed measurements needed to establish the traceability chain and developed uncertainty budgets. Specifically, we have developed uncertainty budgets for pitch, height, and critical dimension (CD) measurements. Some evaluations were performed using samples for which a full traceability chain is not available. We expect to improve the uncertainties further for such samples. At present, the standard uncertainties are estimated to be approximately 0.2% for pitch measurements, 0.4% for step height measurements, and 5 nm for CD measurements in the sub-micrometer range. Similar budgets will be developed for the new tool once it is installed. We will describe our methodology for RMS implementation and the major applications for which it has been used. These include measurements on new NIST/ISMT linewidth standards, a reference tool for CD-scanning electron microscopes (SEMs), metrology on photo-masks, CD-SEM benchmarking, and 193 nm resist shrinkage measurements.

Proceedings Title

Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XVII, Daniel J. Herr, Editor

Volume

5038

Conference Dates

February 24, 2003

Conference Location

Santa Clara, CA

Conference Title

Critical Dimension I

Pub Type

Conferences

Keywords

AFM, calibration, CD linewidth, metrology, reference measurement system, standards, traceability

Citation

Dixson, R. , Vorburger, T. , Guerry, A. , Bennett, M. and Bunday, B. (2003), Implementation of a Reference Measurement System Using CD-AFM, Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XVII, Daniel J. Herr, Editor, Santa Clara, CA (Accessed April 20, 2024)