Abstract
This paper discusses the efforts toward overcoming the difficulty in the inspection and measurement of submicrometer structures of very large-scale integration (VLSI) circuitry. The microelectronic industry has been using finer line-width and spacing to build denser circuitry. When the lines and spacings are smaller than the light wavelength, the traditional optical microscope is no longer able to image the fine lines due to light diffraction.
A new method of surface profiling and dimensional measurement of submicron VLSI structures using scanning tunneling microscopy (STM) has been successfully tested. An improved technique for etching sharp and slender STM probes has been developed, enabling the STM to be applied to high-density, high-rise microelectronic structures and reducing the measurement error caused by the probe geometry. Probes with an ideal tip geometry, with a tip angle less than 3° and a radius of 0.03 µm within 1 µm from the tip, can be consistently produced and are believed to be state-of-the-art. Furthermore, the methods of side wall profiling and true profile reconstruction are developed to avoid the probe geometrical effect, making it possible for STM to obtain an accurate topographical profile without cleaving the sample and viewing it from the edge as needed by scanning electron microscopy (SEM).
Compared to scanning electron microscopy SEM, STM operates in air, provides three-dimensional imaging and yields better resolution; therefore, STM has a greater potential than SEM. The measurement error caused by the geometry of the probe, the only outstanding issue affecting STM accuracy, is explored in detail. The same techniques developed in this study can also be applied to atomic force microscope (AFM), a derivative of STM, for profiling and measuring nonconductive samples.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
M. T Postek and D.C. Joy, Microelectronics dimensional metrology in the scanning electron microscope, ATT Bell Lab. Technical Memorandum,TM #11521–860804–37.
G. Binnig, H. Rohrer, C. Gerber, and E. Weibel, ‘funneling through a controllable vacuum gap, Appl. Phys. Lett. 40: 178–180 (1982).
G. Binnig, H. Rohrer, C. Gerber, and E. Weibel, Surface study by scanning tunneling microscopy, Phys. Rev. Lett. 49: 57–60 (1982).
G. Binnig, H. Rohrer, C. Gerber, and E. Weibel, Vacuum tunneling, Physics 109 and 110b: 2075–2077 (1982).
Y. Kuk and P.J. Silverman, Review: Scanning tunneling microscope instrumentation, Rev. Sci. Instrum. 60: 165–180 (1989).
P.K. Hansma and J. Tersof, Scanning tunneling microscopy, J. Appl. Phys. 62: R1–R23 (1987).
S.Y. Hong, Scanning tunneling microscope application in VLSI submicron metrology,“ Bell Lab. Technical Memorandum, TM #52126–890817–21, 1989.
P.J. Bryant, H.S. Kim, Y.C. Zheng, and R. Yang, Technique for shaping scanning tunneling microscope tips, Rev. Sci. Instrum. 58: 1115 (1987).
Hiroski Morikawa and Keisuke Goto, Reproducible sharp-pointed tip preparation for field ion microscopy by controlled ac polishing, Rev. Sci. Instrum. 59: 2195–2197 (1988).
Mae-Mae Y. Shieh, Summer project report for tungsten probe etching, ATT Bell Laboratories, Internal Memorandum for Record, Aug. 11, 1989.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1997 Springer Science+Business Media New York
About this chapter
Cite this chapter
Hong, S.Y. (1997). Scanning Tunneling Microscopy for Very Large-Scale Integration (VLSI) Inspection. In: Cohen, S.H., Lightbody, M.L. (eds) Atomic Force Microscopy/Scanning Tunneling Microscopy 2. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-9325-3_2
Download citation
DOI: https://doi.org/10.1007/978-1-4757-9325-3_2
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4757-9327-7
Online ISBN: 978-1-4757-9325-3
eBook Packages: Springer Book Archive