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Your search keyword '"Cahill, D.G."' showing total 15 results
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15 results on '"Cahill, D.G."'

5. Phonon-defect scattering in doped silicon by molecular dynamics simulation

Author

Yao, M., Watanabe, T., Schelling, P.K., Keblinski, P.K., Cahill, D.G., and Phillpot, S.R.

Subjects
Molecular dynamics -- Analysis, Silicon compounds -- Spectra, Silicon compounds -- Chemical properties, Electromagnetic waves -- Scattering, Electromagnetic waves -- Research, Physics
Abstract

Molecular dynamics simulations are used for studying the scattering of phonon wave packets of well-defined frequency and polarization from individual point defects and from a field of point defects in Si. The results have shown that the fractions of transmitted and reflected energies have strongly depended on the frequency of the incident phonons and on the mass and concentration of the defects.

Published
2008

6. Hydrogen-mediated quenching of strain-induced surface roughening during gas-source molecular beam epitaxy of fully coherent Si(sub 0.7) Ge(sub 0.3) layers on Si(001)

Author

Spila, T., Cahill, D.G., Desjardins, P., Greene, J.E., Vallionis, A., Guillon, S., H. Kim, Masut, R.A., and Taylor, N.

Subjects
Epitaxy -- Analysis, Germanium -- Research, Silicon -- Research, Hydrogen -- Analysis, Physics
Abstract

Scanning tunneling microscopy (STM), atomic force microscopy (AFM), and x-ray reflectivity (XXR) was used to investigate the effects of varying tetha(sub H) on surface morphological evolution during Si(sub 0.7) Ge(sub 0.3) growth on Si(001) by GS-MBE at temperatures T(sub s)=450, 500, and 55 degrees Celsius and thinknesses t up to the critical value for misfit dislocations. The differences in surface morphological evolution observed suggests that tetha(sub H) plays an important role in mediating the kinetics of strain-induced roughening through changes in film growth rates as well as adatom mean-free paths and step-crossing probabilities.

Published
2002

7. Melting and surface deformation in pulsed laser surface micromodification of Ni-P disks

Author

S.C. Chen, Cahill, D.G., and Grigoropoulos, C.P.

Subjects
Transients (Dynamics) -- Measurement, Laser beams -- Measurement, Engineering and manufacturing industries, Science and technology
Abstract

A study was conducted to investigate the nanosecond pulsed laser-induced transient melting and miniature surface deformation of Ni-P hard disk substrates. The results show the variation of the feature shape in response to different pulse energies of the near-infrared pulsed nanosecond heating laser beam.

Published
2000

8. Determination of the thermal conductivity tensor of the n=7 Aurivillius phase Sr4Bi4Ti7024

Author

Zurbuchen, M.A., Cahill, D.G., Schubert, J., Jia, Y., and Schlom, D.G.

Subjects
ddc:530
Abstract

A challenge in the preparation of advanced materials that exist only as thin films is to establish their properties, particularly when the materials are of low symmetry or the tensor properties of interest are of high rank. Using Sr4Bi4Ti7O24 as an example, we show how the preparation of oriented epitaxial films of multiple orientations enables the thermal conductivity tensor of this tetragonal material with a c-axis length of 64.7 angstrom to be measured. The thermal conductivity tensor coefficients k(33) = 1.10Wm(-1) K-1 and k(11) = k(22) = 1.80Wm(-1) K-1 were determined by growing epitaxial Sr4Bi4Ti7O24 films on (100), (110), and (111) SrTiO3 substrates. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733616]

Published
2012
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9. Ultra-low thermal conductivity in W/[Al.sub.2][O.sub.3] nanolaminates

Author

Costescu, R.M., Cahill, D.G., Fabreguette, F. H., Sechrist, Z. A., and George, S.M.

Subjects
Thin films -- Design and construction -- Properties -- Research, Insulation (Heat) -- Design and construction -- Research, Dielectric films -- Design and construction -- Properties -- Research, Insulating materials -- Design and construction -- Research, Science and technology, Design and construction, Research, Properties
Abstract

Atomic layer deposition and magnetron sputter deposition were used to synthesize thin-film multilayers of W/[Al.sub.2][O.sub.3]. With individual, layers only a few nanometers thick, the high interface density produced a strong impediment to heat transfer, giving rise to a thermal conductivity of ~0.6 watts per meter per kelvin. This result suggests that high densities of interfaces between dissimilar materials may provide a route for the production of thermal barriers with ultra-low thermal conductivity., Materials with structure on nanometer-length scales are being studied for their promise of providing novel optical, electrical, magnetic, or mechanical properties. The thermal properties of nanostructured materials, however, have received [...]

Published
2004

11. Report on 6th U.S.–Japan Joint Seminar on Nanoscale Transport Phenomena—Science and Engineering

Author

Borca-Tasciuc, T., primary, Cahill, D.G., additional, Chen, G., additional, Cronin, S.B., additional, Daiguji, H., additional, Dames, C., additional, Fushinobu, K., additional, Inoue, T., additional, Majumdar, A., additional, Maruyama, S., additional, Miyazaki, K., additional, Matsumoto, M., additional, Norris, P.M., additional, Shi, L., additional, Shibahara, M., additional, Shannon, M., additional, Shiomi, J., additional, Taguchi, Y., additional, Takahashi, K., additional, Tsuruta, T., additional, Volz, S.G., additional, Wang, E., additional, Xu, X.F., additional, Yang, B., additional, and Yang, R.G., additional

Published
2008
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14. GaAs-based metal-insulator-semiconductor structures with low interface traps using molecular beam epitaxy and chemical vapor deposition

Author

Park, D.G., Tao, M., Reed, J., Suzue, K., Botchkarev, A.E., Fan, Z., Gao, G.B., Chey, S.J., Nostrand, J. Van, Cahill, D.G., and Morko, H.

Abstract

The performance of GaAs-based field-effect transistors (FETs) in switching and power applications can be enhanced substantially by employing a metal-insulator-semiconductor (MIS) structure. Attempts thus far have fallen short due to large interface trap concentrations, frequency dispersion, and hysteresis. By taking advantage of an in-situ process approach, we successfully gated insulator -- GaAs structures with excellent interfacial properties. The structures utilize a Si interface layer or a composite Si/Ge layer grown on GaAs followed by a Si 3 N 4 dielectric layer, all using a III-V molecular beam epitaxy (MBE) system connected by an ultrahigh vacuum transfer tube to an adjacent electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (CVD) system. This pseudo-in-situ feature in concert with recently implemented vacuum connected scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) allows investigations of the essential interface layers. High/low frequency capacitance-voltage, conductance versus frequency, and metal-insulator-semiconductor field-effect transistors (MISFETs) were used for a comprehensive characterization of the n-type MIS structures. From the stringent conductance measurements, interface state densities in the high 10 eV cm have been obtained. The hysteresis is about 150 mV for a field swing of +4 to −4 MV/cm. The frequency dispersion is nearly zero except near inversion where its value is about 100 mV. Self aligned gate depletion mode MISFETs having 3 μm gate lengths exhibited transconductances of 169 mS/mm for the pseudomorphic InGaAs channels and about 100-140 mS/mm for GaAs channels.

Published
1995
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