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High-resolution picosecond acoustic microscopy for non-invasive characterization of buried interfaces

Published online by Cambridge University Press:  01 May 2006

Shriram Ramanathan  and
David G. Cahill
Shriram Ramanathan*
Affiliation:
Components Research, Intel Corporation, Hillsboro, Oregon 97124
David G. Cahill
Affiliation:
Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801
*
a) Address all correspondence to this author.Present address: Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138. e-mail: [email protected]
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Abstract

Non-destructive investigation of buried interfaces at high-resolution is critical for integrated circuit and advanced packaging research and development. In this letter, we present a novel non-contact microscopy technique using ultrahigh frequency (GHz range) longitudinal acoustic pulses to form images of interfaces and layers buried deep inside a silicon device. This method overcomes fundamental limitations of conventional scanning acoustic microscopy by directly generating and detecting the acoustic waves on the surface of the sample using an ultrafast pump-probe optical technique. We demonstrate our method by imaging copper lines buried beneath a 6-μm silicon wafer; the lateral spatial resolution of 3 μm is limited by the laser spot size. In addition to the high lateral spatial resolution, the technique has picosecond (ps) time resolution and therefore will enable imaging individual interconnect layers in multi-layer stacked devices.

Keywords

BondingScanning acoustic microscopy (SAM)Thin film
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 5 , May 2006 , pp. 1204 - 1208
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1.Bohr, M.T.: Interconnect scaling-the real limiter to high performance ULSI. Solid State Technol. 39, 105 (1996).Google Scholar
2.Costescu, R.M., Bullen, A.J., Matamis, G., O'Hara, K.E., Cahill, D.G.: Thermal conductivity and sound velocities of hydrogen-silsesquioxane low-k dielectrics. Phys. Rev. B 65, 0942051 (2002).CrossRefGoogle Scholar
3.Davis, J.A., Venkatesan, R., Kaloyeros, A., Beylansky, M., Souri, S.J., Banerjee, K., Saraswat, K.C., Rahman, A., Reif, R., Meindl, J.D.: Interconnect limits on gigascale integration (GSI) in the 21st century. Proc. IEEE. 89, 305 (2001).CrossRefGoogle Scholar
4.Black, B., Nelson, D.W., Webb, C., and Samra, N.: Proceedings of IEEE Int'l. Conference on Computer Design, 316, San Jose, CA (2004) p. 316.Google Scholar
5.Briggs, G.A.D.: An Introduction to Scanning Acoustic Microscopy (Oxford University Press, Oxford, UK, 1985).Google Scholar
6.Quate, C.F.: Acoustic microscopy. Phys. Today 38, 34 (1985).CrossRefGoogle Scholar
7.Attal, J., Truong, N. Quang, Cambon, G., and Saurel, J.M.: Acoustic microscopy: Recent progress in imaging through opaque materials, in Proceedings of the 2nd Oxford Conference, Microscopy of Semiconducting Materials, edited by Cullis, A.G., and Joy, D.C. (IOP, Bristol, UK, 1981), p. 441.Google Scholar
8.Hao, H-Y., Maris, H.J.: Dispersion of the long-wavelength phonons in Ge, Si, GaAs, quartz, and sapphire. Phys. Rev. B 63, 224301 (2001).CrossRefGoogle Scholar
9.Duquesne, J-Y., Perrin, B.: Ultrasonic attenuation in a quasicrystal studied by picosecond acoustics as a function of temperature and frequency. Phys. Rev. B 68, 134205 (2003).CrossRefGoogle Scholar
10.Daly, B.C., Norris, T.B., Chen, J., Khurgin, J.B.: Picosecond acoustic phonon pulse propagation in silicon. Phys. Rev. B 70, 214307 (2004).CrossRefGoogle Scholar
11.Hara, K.E. O, Hu, X., Cahill, D.G.: Characterization of nanostructured metal films by picosecond acoustics and interferometry. J. Appl. Phys. 90, 4852 (2001).Google Scholar
12.Wright, O.B.: Ultrafast nonequilibrium stress generation in gold and silver. Phys. Rev. B 49, 9985 (1984).CrossRefGoogle Scholar
13.Tas, G., Loomis, J.J., Maris, H.J., III, A.A. Bailes, Seiberling, L.E.: Picosecond ultrasonics study of the modification of interfacial bonding by ion implantation. Appl. Phys. Lett. 72, 2235 (1998).CrossRefGoogle Scholar
14.Morrow, P., Kobrinsky, M.J., Ramanathan, S., Park, C-M., Harmes, M., Ramachandrarao, V., Park, H., Kloster, G., List, S., and Kim, S.: Wafer-level 3D interconnects via Cu bonding, in Advanced Metallization Conference 2004, edited by Erb, D., Ramm, P., Masu, K., and Osaki, A., (Materials Research Society, Warrendale, PA, 2005), p. 125.Google Scholar
15.Huxtable, S., Cahill, D.G., Fauconnier, V., White, J.O., Zhao, J-C.: Thermal conductivity imaging at micrometre-scale resolution for combinatorial studies of materials. Nat. Mater. 3, 298 (2004).CrossRefGoogle ScholarPubMed
16.Hao, H-Y., Maris, H.J.: Experiments with acoustic solitons in crystalline solids. Phys. Rev. B 64, 064302 (2001).CrossRefGoogle Scholar