Progress Towards Accurate Metrology Using Atomic Force Microscopy
T Mcwaid, J Schneir, John S. Villarrubia, Ronald G. Dixson, V W. Tsai
Accurate metrology using atomic force microscopy (AFM) requires accurate control of the tip position, an estimate of the tip geometry, and an understanding of the tip-surface interaction forces. We describe recent progress at NIST towards accurate AFM metrology. We begin with a brief introduction to the potential applications of accurate AFM metrology within the semiconductor industry. Next, we describe the technological infrastructure required before industry personnel can successfully use AFM for repeatable, reproducible, and accurate measurements. NIST''s programmatic response to the identified needs is then outlined. We give particular attention to the development of a calibrated atomic force microscope (C-AFM), since the development of this instrument is essential to the successful completion of most of our specific projects. Measurements of a prototype pitch/height artifact are presented. Next we summarize our efforts toward the development of a viable method of characterizing probe tip geometry. Finally, we present a linewidth measurement that has been bracketed through the use of mathematical morphology for tip geometry estimation.
Chapter in Semiconductor Characterization: Present Status and Future Needs, W.M. Bullis, D.G. Seiler, A.C. Diebold, Eds
AIP Press, New York, NY
AFM, atomic force microscopy, C-AFM, calibration, CD, critical dimension, dimensional metrology, height, linewidth, mathematical morphology, pitch, tip estimation