Department of Mechanical Engineering
Stanford University
Principal Investigator
Kenneth E. Goodson
Phonon Scattering in Silicon and Polysilicon Films
Sponsors:
SRC, NSF, Intel, AMD
Collaborators:
Professor Simon Wong, Stanford Electrical Engineering The basic physics of phonon conduction in dielectrics and semiconductors has been the focus of research for more than a century. However, recent improvements in nanofabrication technologies have enabled new classes of experiments involving silicon films of near perfect crystalline quality. The MEMS and semiconductor communities need the thermal conductivities of these materials for a variety of applications, and these data are can provide breakthrough information about phonon conduction physics.
We developed measurements of in-plane silicon thin film thermal conductivities in the late 1990's using Joule heating and thermometry and the best contemporary SOI substrates, which augment lateral heat spreading. The thermal conductivity data over a broad range of temperatures and film thicknesses were consistent with solutions to the phonon Boltzmann transport equation accounting for boundary scattering. Room temperature data for very thin silicon films (below 100nm) showed a size effect of nearly 50% at room temperature and this result was compared with predictions to help separate the relative contributions of phonons to the overall thermal conductivity in bulk silicon. A suspended MEMS structure was developed for measuring the thermal conductivities of doped and undoped polycrystalline silicon films, in which the coupled scattering effects of grain boundaries, interfaces, and dopant impurities were investigated as a function of film thickness and temperature. More recent data have determined the impact of localized phonon nonequilibrium on lateral conduction in SOI films, which elevates the thermal resistance compared to solutions based on Fourier's law.
PROJECT PUBLICATIONS
Marconnet, A.M., Kodama, T., Asheghi, M., and Goodson, K.E., "Phonon Conduction in Periodically Porous Silicon Nanobridges," Nanoscale and Microscale Thermophysical Engineering, under review.
Rowlette, J.A., and Goodson, K.E., 2008, "Fully-Coupled, Nonequilibrium, Electron-Phonon Transport in Nanometer-Scale Silicon FETs," IEEE Transactions on Electronic Devices, Vol. 55, pp. 220-232.
Sinha, S., and Goodson, K.E., 2006, "Thermal Conduction in Sub-100nm Transistors," Microelectronics Journal, Vol. 37, pp. 1148-1157.
Pop, E., and Goodson, K.E., 2006, "Thermal Phenomena in Nanoscale Transistors," Journal of Electronic Packaging, Vol. 128, pp. 102-108.
Sinha S., and Goodson, K.E., 2005, "Review: Multiscale Thermal Modeling in Nanoelectronics," International Journal for Multiscale Computational Engineering, Vol. 3, pp. 107-133.
McConnell, A.D., and Goodson, K.E., 2005, "Thermal Conduction in Silicon Micro and Nanostructures," Annual Review of Heat Transfer, Vol. 14, pp. 129-168.
Pop, E., Dutton, R.W., and Goodson, K.E., 2004, "Analytic Band Monte Carlo Model for Electron Transport Modeling in Si Including Acoustic and Optical Phonon Dispersion," Journal of Applied Physics, Vol. 96, pp. 4998-5005.
Cahill, D.G., Ford, W.K., Goodson, K.E., Mahan, G.D., Majumdar, A., Maris, H.J., Merlin, R., and Phillpot, S.R., 2003, "Nanoscale Thermal Transport," Journal of Applied Physics, Vol. 93, 793-818.
Asheghi, M., Kurabayashi, K., Kasnavi, K., and Goodson, K.E., 2002, "Thermal Conduction in Doped Single-Crystal Silicon Films," Journal of Applied Physics, Vol. 91, pp. 5079-5088.
McConnell, A.D., Srinivasan, U., Asheghi, M., and Goodson, K.E., 2001, "Thermal Conductivity of Doped Polysilicon," IEEE/ASME Journal of MicroElectroMechanical Systems, Vol. 10, pp. 360-369.
Sverdrup, P.G., Sinha, S., Uma, S., Asheghi, M., and Goodson, K.E., 2001, "Measurement of Ballistic Phonon Conduction Near Hotspots in Silicon," Applied Physics Letters, Vol. 78, pp. 3331-3333.
Uma, S., McConnell, A.D., Asheghi, M., Kurabayashi, K., and Goodson, K.E., 2001, "Temperature Dependent Thermal Conductivity of Undoped Polycrystalline Silicon Layers," International Journal of Thermophysics, Vol. 22, pp. 605-616.
Touzelbaev, M.N., and Goodson, K.E, 2001, "Impact of Experimental Timescale and Geometry on Thin-Film Thermal Property Measurements," International Journal of Thermophysics, Vol. 22, pp. 243-263.
Sverdrup, P.G., Ju, Y.S.,and Goodson, K.E., 2001, "Sub-Continuum Simulations of Heat Conduction in Silicon-on-Insulator Transistors," ASME Journal of Heat Transfer, Vol. 123, pp. 30-37.
Goodson, K.E., and Ju, Y.S., 1999, "Heat Conduction in Novel Electronic Films," in the Annual Review of Materials Science, E.N. Kaufmann et al., eds., Annual Reviews, Palo Alto, CA, Vol. 29, pp. 261-293.
Ju, Y.S., and Goodson, K.E., 1999, "Phonon Scattering in Silicon Films of Thickness Below 100 nm," Applied Physics Letters, Vol. 74, pp. 3005-3007.
Asheghi, M., Touzelbaev, M.N., Goodson, K.E., Leung, Y.K., and Wong, S.S., 1998, "Temperature-Dependent Thermal Conductivity of Single-Crystal Silicon Layers in SOI Substrates," ASME Journal of Heat Transfer, Vol. 120, pp. 31-36.
Asheghi, M., Leung, Y.K., Wong, S.S., and Goodson, K.E., 1997, "Phonon-Boundary Scattering in Thin Silicon Layers," Applied Physics Letters, Vol. 71, pp. 1798-1800.
Ju, Y.S., and Goodson, K.E., 1997, "Size Effect on the Thermal Conductivity of Silicon-on-Insulator Devices under Electrostatic Discharge (ESD) Conditions," Japanese Journal of Applied Physics, Part 2, Vol. 36, pp. L798-L800.
Goodson, K.E., Flik, M.I., Su, L.T., and Antoniadis, D.A., 1995, "Prediction and Measurement of Temperature Fields in Silicon-on-Insulator Electronic Circuits," ASME Journal of Heat Transfer, Vol. 117, pp. 574-581.
Su, L.T., Chung, J.E., Antoniadis, D.A., Goodson, K.E., and Flik, M.I., 1994, "Measurement and Modeling of Self-Heating in SOI nMOSFETS," IEEE Transactions on Electron Devices, Vol. 41, pp. 69-75.
Goodson, K.E., and Flik, M.I., 1994, "Solid-Layer Thermal-Conductivity Measurement Techniques," Applied Mechanics Reviews, Vol. 47, pp. 101-112.
Goodson, K.E., and Flik, M.I., 1992, "Effect of Microscale Thermal Conduction on the Packing Limit of Silicon-on-Insulator Electronic Devices," IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Vol. 15, pp. 715-722.