Translator Disclaimer
24 May 2004 Reference metrology using a next-generation CD-AFM
Author Affiliations +
International SEMATECH (ISMT) and the National Institute of Standards and Technology (NIST) are working together to improve the traceability of AFM dimensional metrology in semiconductor manufacturing. Due to the unique metrology requirements and the rapid change in the semiconductor industry, relevant standards are often not available. Consequently, there is often no traceable linkage between the realization of the SI (Systeme International d’Unites, or International System of Units) unit of length -- the meter -- and measurements in the fab line. To improve this situation, we have implemented a Reference Measurement System (RMS) using a next-generation critical-dimension atomic force microscope (CD-AFM). We performed measurements needed to establish a traceability chain and developed uncertainty budgets for pitch, height, and critical dimension (CD) measurements. 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. Further improvement in these uncertainties is expected with the use of newer samples for scale and tip calibration. 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. As part of the NIST/ISMT linewidth standards project, we are performing an extensive comparison experiment of AFM and TEM (transmission electron microscopy) measurements of linewidth.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ronald Dixson and Angela Guerry "Reference metrology using a next-generation CD-AFM", Proc. SPIE 5375, Metrology, Inspection, and Process Control for Microlithography XVIII, (24 May 2004);


Submicron calibration strategy for CD control
Proceedings of SPIE (September 13 1996)
Characteristics of accuracy for CD metrology
Proceedings of SPIE (June 14 1999)
CD-AFM reference metrology at NIST and SEMATECH
Proceedings of SPIE (May 10 2005)

Back to Top