Wayne Ford - Academia.edu (original) (raw)
Papers by Wayne Ford
Journal of Vacuum Science & Technology A, 1994
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1990
... Sci. Instrum. 61, 968 (1990). "CB Duke, A. Paton, WK Ford, A. Kahn, and J.Carcili, P... more ... Sci. Instrum. 61, 968 (1990). "CB Duke, A. Paton, WK Ford, A. Kahn, and J.Carcili, Phys. Rev. В 20,803 (1982). 7J. Carelli and A. Kahn, Surf. Sci. ... Í52, 761 ( 19881; Phys. Rev. В 39, 7744 (1989). ''A. Taieb-lbrahimi, R. Ludeke, RM Feenstra, and A. R McLean, J. Vac. Sci. Technol. ...
Journal of Vacuum Science & Technology A, 1991
Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (i... more Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (in ultrahigh vacuum) MgO(001) surface using beam energy modulation to avoid electrical charging. Dynamic LEED analysis of the data indicates: (1) an interlayer relaxation of (1{plus minus}2)% and a rumple of the first layer ions of (5{plus minus}2.5)%; (2) a new attenuation model containing no adjustable parameters gives
Journal of Vacuum Science & Technology A, 1991
Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (i... more Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (in ultrahigh vacuum) MgO(001) surface using beam energy modulation to avoid electrical charging. Dynamic LEED analysis of the data indicates: (1) an interlayer relaxation of (1{plus minus}2)% and a rumple of the first layer ions of (5{plus minus}2.5)%; (2) a new attenuation model containing no adjustable parameters gives
Journal of Vacuum Science & Technology A, 1992
Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K a... more Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward
Journal of Applied Physics, 2003
Rapid progress in the synthesis and processing of materials with structure on nanometer length sc... more Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid-solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime-experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3 method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology.
Journal of Vacuum Science & Technology A, 1994
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1990
... Sci. Instrum. 61, 968 (1990). "CB Duke, A. Paton, WK Ford, A. Kahn, and J.Carcili, P... more ... Sci. Instrum. 61, 968 (1990). "CB Duke, A. Paton, WK Ford, A. Kahn, and J.Carcili, Phys. Rev. В 20,803 (1982). 7J. Carelli and A. Kahn, Surf. Sci. ... Í52, 761 ( 19881; Phys. Rev. В 39, 7744 (1989). ''A. Taieb-lbrahimi, R. Ludeke, RM Feenstra, and A. R McLean, J. Vac. Sci. Technol. ...
Journal of Vacuum Science & Technology A, 1991
Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (i... more Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (in ultrahigh vacuum) MgO(001) surface using beam energy modulation to avoid electrical charging. Dynamic LEED analysis of the data indicates: (1) an interlayer relaxation of (1{plus minus}2)% and a rumple of the first layer ions of (5{plus minus}2.5)%; (2) a new attenuation model containing no adjustable parameters gives
Journal of Vacuum Science & Technology A, 1991
Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (i... more Low-energy electron diffraction (LEED) beam intensities were measured from the freshly cleaved (in ultrahigh vacuum) MgO(001) surface using beam energy modulation to avoid electrical charging. Dynamic LEED analysis of the data indicates: (1) an interlayer relaxation of (1{plus minus}2)% and a rumple of the first layer ions of (5{plus minus}2.5)%; (2) a new attenuation model containing no adjustable parameters gives
Journal of Vacuum Science & Technology A, 1992
Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K a... more Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward
Journal of Applied Physics, 2003
Rapid progress in the synthesis and processing of materials with structure on nanometer length sc... more Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid-solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime-experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3 method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology.