Gary Rubloff - Academia.edu (original) (raw)
Papers by Gary Rubloff
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films
The surface chemistry of reactive precursors, such as those employed in CVD, often exhibits a str... more The surface chemistry of reactive precursors, such as those employed in CVD, often exhibits a strongly self-limiting character in adsorption/reaction. This self-limiting behavior is directly exploited in atomic layer deposition (ALD), where alternating exposures of the different ...
The fabrication of 3-d nanostructures can serve as building blocks for a vast range of on-chip en... more The fabrication of 3-d nanostructures can serve as building blocks for a vast range of on-chip energy storage devices. The ability to precisely control material deposition inside these structures is attractive due to its potential for integration with conventional fabrication technology commonly used in MEMS and NEMS devices. This talk discusses how two key-processing technologies, namely anodic aluminum oxide (AAO) and atomic layer deposition (ALD) are implemented to create metal-insulator-metal (MIM) nanocapacitors. These highly scalable processes produce structure arrays exhibiting high power and energy densities, which makes such structures ideal for integration systems-on-a-chip technology where autonomous energy generation and storage is required.
... Mv WSHIHaXW MHI\HaMOOSTQSa SS\OX M\T]WX_\TaXUWXdITS]WX_\TWSlSWS\KSopDS aSZUSWMa_WSHI]\MOH SWS... more ... Mv WSHIHaXW MHI\HaMOOSTQSa SS\OX M\T]WX_\TaXUWXdITS]WX_\TWSlSWS\KSopDS aSZUSWMa_WSHI]\MOH SWSaDS\MZUOI lXOTQSlXWSQSI\]HS\aaXaDSTMaMMKn_IHIaIX\ ... HI]\MOHI\aDS UWX]WMZo TTIaIX\MOUWXKSHHI\]dMWIMQOSHXl HFHaSZw ...
Dynamic, physically based simulation has proved very effective in representing the time- dependen... more Dynamic, physically based simulation has proved very effective in representing the time- dependent behavior of equipment, process, sensor and control systems. We have developed a system-level dynamic simulator for an 8" CVD cluster tool (ULVAC-ERA1000). The simulator incorporates models for equipment, process and control systems, representing time-dependent system level behavior through the imposition of equipment controller recipes for pump-down, process and venting cycles. Multistage pumping systems (Roots-mechanical and turbo- mechanical) are modeled using compression ratios, nominal speeds, and volumes to reflect actual behavior, validated against experiments on the Ulvac tool. The process simulator is derived from the work of Hsieh et al. The Ulvac simulator is applied to optimization of deposition rate and WF6 utilization, analysis of experimental data for recipe improvement, and development and debugging of equipment controller software and operation.
A quadrupole mass spectrometer (QMS) and an acoustic sensor have been used for real-time process ... more A quadrupole mass spectrometer (QMS) and an acoustic sensor have been used for real-time process monitoring and thickness metrology in W-CVD (3 H2 + WF6 → W + 6 HF) using an Ulvac cluster tool. The QMS recorded the time evolution of the partial pressures for the reactants (H2 /WF6) and the HF product, while the acoustic sensor monitored variations in the average molecular weight of the gas mixture in the reactor through the process cycle. Integrated signals from both sensors gave in-situ thickness estimates accurate to within ~7% cf. actual post-process thickness measurements, despite the poor reactant conversion rate (just a few percent) in the tool. For mainstream processes involving blanket CVD, where much higher conversion rates (~50%) are typical, we expect thickness metrology capability in the range of 1-2%, making these techniques attractive for thickness metrology and associated process control, in addition to fault detection and process chemistry determination.
Physical Review Letters, 1973
We consider a case, the far-ultraviolet spectrum of an ionic crystal, where the local-field effec... more We consider a case, the far-ultraviolet spectrum of an ionic crystal, where the local-field effects on the optical properties can easily be understood. The results show how local-field effects modify the optical properties of solids and complicate their interpretation and comparison with theory.
Most conventional chemical vapor deposition (CVD) systems do not have the spatial actuation and s... more Most conventional chemical vapor deposition (CVD) systems do not have the spatial actuation and sensing capabilities necessary to control deposition uniformity, or to intentionally induce nonuni- form deposition patterns for single-wafer combinatorial CVD experiments. In an effort to address this limitation, a novel CVD reactor system has been developed that can explicitly control the spa- tial profile of gas-phase chemical
Chemistry of Materials, 2015
We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phospho... more We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phosphorousoxynitride (LiPON) using lithium tert-butoxide (LiO t Bu), H 2 O, trimethylphosphate (TMP), and plasma N 2 ( P N 2 ) as precursors. We use in-situ spectroscopic ellipsometry to determine growth rates for process optimization to design a rational, quaternary precursor ALD process where only certain substrate−precursor chemical reactions are favorable. We demonstrate via in-situ XPS tunable nitrogen incorporation into the films by variation of the P N 2 dose and find that ALD films over approximately 4.5% nitrogen are amorphous, whereas LiPON ALD films with less than 4.5% nitrogen are polycrystalline. Finally, we characterize the ionic conductivity of the ALD films as a function of nitrogen content and demonstrate their functionality on a model battery electrodea Si anode on a Cu current collector.
While there are numerous types of electronic learning environments including collaboratories, con... more While there are numerous types of electronic learning environments including collaboratories, construction toolkits, systems with "scaffolding" and simulations, it is difficult to find authoring tools to build these systems. We have developed an application framework for constructing simulation-based learning environments called SimPLE (Simulated Processes in a Learning Environment). Environments developed with SimPLE use dynamic simulations and visualizations to represent realistic
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1999
ABSTRACT
ACS Applied Materials & Interfaces, 2015
One of the greatest obstacles for the realization of the nonaqueous Li-O2 battery is finding a so... more One of the greatest obstacles for the realization of the nonaqueous Li-O2 battery is finding a solvent that is chemically and electrochemically stable under cell operating conditions. Dimethyl sulfoxide (DMSO) is an attractive candidate for rechargeable Li-O2 battery studies; however, there is still significant controversy regarding its stability on the Li-O2 cathode surface. We performed multiple experiments (in situ XPS, FTIR, Raman, and XRD) which assess the stability of the DMSO-Li2O2 interface and report perspectives on previously published studies. Our electrochemical experiments show long-term stable cycling of a DMSO-based operating Li-O2 cell with a platinum@carbon nanotube core-shell cathode fabricated via atomic layer deposition, specifically with >45 cycles of 40 h of discharge per cycle. This work is complemented by density functional theory calculations of DMSO degradation pathways on Li2O2. Both experimental and theoretical evidence strongly suggests that DMSO is chemically and electrochemically stable on the surface of Li2O2 under the reported operating conditions.
Lab on a chip, Jan 31, 2015
The human gut is over a meter in length, liquid residence times span several hours. Recapitulatin... more The human gut is over a meter in length, liquid residence times span several hours. Recapitulating the human gut microbiome "on chip" holds promise to revolutionize therapeutic strategies for a variety of diseases, as well as for maintaining homeostasis in healthy individuals. A more refined understanding of bacterial-bacterial and bacterial-epithelial cell signalling is envisioned and such a device is a key enabler. Indeed, significant advances in the study of bacterial cell-cell signalling have been reported, including at length and time scales of the cells and their responses. Few reports exist, however, where signalling events that span physiologically relevant time scales are monitored and coordinated. Here, we employ principles of biofabrication to assemble, in situ, cell communities that are (i) spatially adjacent within partitioned microchannels for studying near communication and (ii) distally connected within longitudinal microfluidic networks so as to mimic long...
Physical review. B, Condensed matter, Jan 15, 1986
Proceedings of the 1999 conference on Computer support for collaborative learning - CSCL '99, 1999
Reviewing past events has been useful in many domains. Videotapes and flight data recorders provi... more Reviewing past events has been useful in many domains. Videotapes and flight data recorders provide invaluable technological help to sports coaches or aviation engineers. Similarly, providing learners with a readable recording of their actions may help them monitor their behavior, reflect on their progress, and experiment with revisions of their experiences. It may also facilitate active collaboration among dispersed learning communities. Learning histories can help students and professionals make more effective use of digital library searching, word processing tasks, computer-assisted design tools, electronic performance support systems, and web navigation.
NATO Science for Peace and Security Series B: Physics and Biophysics, 2010
E. Gusev et al. (eds.), Advanced Materials and Technologies for Micro/Nano-Devices, ... Sensors a... more E. Gusev et al. (eds.), Advanced Materials and Technologies for Micro/Nano-Devices, ... Sensors and Actuators, DOI 10.1007/978-90-481-3807-4_22, © Springer Science + Business Media BV 2010 ... REZA GHODSSI1,*, PETER DYKSTRA1, MARIANA MEYER2, STEPHAN ...
IFMBE Proceedings, 2010
ABSTRACT
IFMBE Proceedings, 2010
ABSTRACT
IFMBE Proceedings, 2010
ABSTRACT
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films
The surface chemistry of reactive precursors, such as those employed in CVD, often exhibits a str... more The surface chemistry of reactive precursors, such as those employed in CVD, often exhibits a strongly self-limiting character in adsorption/reaction. This self-limiting behavior is directly exploited in atomic layer deposition (ALD), where alternating exposures of the different ...
The fabrication of 3-d nanostructures can serve as building blocks for a vast range of on-chip en... more The fabrication of 3-d nanostructures can serve as building blocks for a vast range of on-chip energy storage devices. The ability to precisely control material deposition inside these structures is attractive due to its potential for integration with conventional fabrication technology commonly used in MEMS and NEMS devices. This talk discusses how two key-processing technologies, namely anodic aluminum oxide (AAO) and atomic layer deposition (ALD) are implemented to create metal-insulator-metal (MIM) nanocapacitors. These highly scalable processes produce structure arrays exhibiting high power and energy densities, which makes such structures ideal for integration systems-on-a-chip technology where autonomous energy generation and storage is required.
... Mv WSHIHaXW MHI\HaMOOSTQSa SS\OX M\T]WX_\TaXUWXdITS]WX_\TWSlSWS\KSopDS aSZUSWMa_WSHI]\MOH SWS... more ... Mv WSHIHaXW MHI\HaMOOSTQSa SS\OX M\T]WX_\TaXUWXdITS]WX_\TWSlSWS\KSopDS aSZUSWMa_WSHI]\MOH SWSaDS\MZUOI lXOTQSlXWSQSI\]HS\aaXaDSTMaMMKn_IHIaIX\ ... HI]\MOHI\aDS UWX]WMZo TTIaIX\MOUWXKSHHI\]dMWIMQOSHXl HFHaSZw ...
Dynamic, physically based simulation has proved very effective in representing the time- dependen... more Dynamic, physically based simulation has proved very effective in representing the time- dependent behavior of equipment, process, sensor and control systems. We have developed a system-level dynamic simulator for an 8" CVD cluster tool (ULVAC-ERA1000). The simulator incorporates models for equipment, process and control systems, representing time-dependent system level behavior through the imposition of equipment controller recipes for pump-down, process and venting cycles. Multistage pumping systems (Roots-mechanical and turbo- mechanical) are modeled using compression ratios, nominal speeds, and volumes to reflect actual behavior, validated against experiments on the Ulvac tool. The process simulator is derived from the work of Hsieh et al. The Ulvac simulator is applied to optimization of deposition rate and WF6 utilization, analysis of experimental data for recipe improvement, and development and debugging of equipment controller software and operation.
A quadrupole mass spectrometer (QMS) and an acoustic sensor have been used for real-time process ... more A quadrupole mass spectrometer (QMS) and an acoustic sensor have been used for real-time process monitoring and thickness metrology in W-CVD (3 H2 + WF6 → W + 6 HF) using an Ulvac cluster tool. The QMS recorded the time evolution of the partial pressures for the reactants (H2 /WF6) and the HF product, while the acoustic sensor monitored variations in the average molecular weight of the gas mixture in the reactor through the process cycle. Integrated signals from both sensors gave in-situ thickness estimates accurate to within ~7% cf. actual post-process thickness measurements, despite the poor reactant conversion rate (just a few percent) in the tool. For mainstream processes involving blanket CVD, where much higher conversion rates (~50%) are typical, we expect thickness metrology capability in the range of 1-2%, making these techniques attractive for thickness metrology and associated process control, in addition to fault detection and process chemistry determination.
Physical Review Letters, 1973
We consider a case, the far-ultraviolet spectrum of an ionic crystal, where the local-field effec... more We consider a case, the far-ultraviolet spectrum of an ionic crystal, where the local-field effects on the optical properties can easily be understood. The results show how local-field effects modify the optical properties of solids and complicate their interpretation and comparison with theory.
Most conventional chemical vapor deposition (CVD) systems do not have the spatial actuation and s... more Most conventional chemical vapor deposition (CVD) systems do not have the spatial actuation and sensing capabilities necessary to control deposition uniformity, or to intentionally induce nonuni- form deposition patterns for single-wafer combinatorial CVD experiments. In an effort to address this limitation, a novel CVD reactor system has been developed that can explicitly control the spa- tial profile of gas-phase chemical
Chemistry of Materials, 2015
We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phospho... more We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phosphorousoxynitride (LiPON) using lithium tert-butoxide (LiO t Bu), H 2 O, trimethylphosphate (TMP), and plasma N 2 ( P N 2 ) as precursors. We use in-situ spectroscopic ellipsometry to determine growth rates for process optimization to design a rational, quaternary precursor ALD process where only certain substrate−precursor chemical reactions are favorable. We demonstrate via in-situ XPS tunable nitrogen incorporation into the films by variation of the P N 2 dose and find that ALD films over approximately 4.5% nitrogen are amorphous, whereas LiPON ALD films with less than 4.5% nitrogen are polycrystalline. Finally, we characterize the ionic conductivity of the ALD films as a function of nitrogen content and demonstrate their functionality on a model battery electrodea Si anode on a Cu current collector.
While there are numerous types of electronic learning environments including collaboratories, con... more While there are numerous types of electronic learning environments including collaboratories, construction toolkits, systems with "scaffolding" and simulations, it is difficult to find authoring tools to build these systems. We have developed an application framework for constructing simulation-based learning environments called SimPLE (Simulated Processes in a Learning Environment). Environments developed with SimPLE use dynamic simulations and visualizations to represent realistic
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1999
ABSTRACT
ACS Applied Materials & Interfaces, 2015
One of the greatest obstacles for the realization of the nonaqueous Li-O2 battery is finding a so... more One of the greatest obstacles for the realization of the nonaqueous Li-O2 battery is finding a solvent that is chemically and electrochemically stable under cell operating conditions. Dimethyl sulfoxide (DMSO) is an attractive candidate for rechargeable Li-O2 battery studies; however, there is still significant controversy regarding its stability on the Li-O2 cathode surface. We performed multiple experiments (in situ XPS, FTIR, Raman, and XRD) which assess the stability of the DMSO-Li2O2 interface and report perspectives on previously published studies. Our electrochemical experiments show long-term stable cycling of a DMSO-based operating Li-O2 cell with a platinum@carbon nanotube core-shell cathode fabricated via atomic layer deposition, specifically with >45 cycles of 40 h of discharge per cycle. This work is complemented by density functional theory calculations of DMSO degradation pathways on Li2O2. Both experimental and theoretical evidence strongly suggests that DMSO is chemically and electrochemically stable on the surface of Li2O2 under the reported operating conditions.
Lab on a chip, Jan 31, 2015
The human gut is over a meter in length, liquid residence times span several hours. Recapitulatin... more The human gut is over a meter in length, liquid residence times span several hours. Recapitulating the human gut microbiome "on chip" holds promise to revolutionize therapeutic strategies for a variety of diseases, as well as for maintaining homeostasis in healthy individuals. A more refined understanding of bacterial-bacterial and bacterial-epithelial cell signalling is envisioned and such a device is a key enabler. Indeed, significant advances in the study of bacterial cell-cell signalling have been reported, including at length and time scales of the cells and their responses. Few reports exist, however, where signalling events that span physiologically relevant time scales are monitored and coordinated. Here, we employ principles of biofabrication to assemble, in situ, cell communities that are (i) spatially adjacent within partitioned microchannels for studying near communication and (ii) distally connected within longitudinal microfluidic networks so as to mimic long...
Physical review. B, Condensed matter, Jan 15, 1986
Proceedings of the 1999 conference on Computer support for collaborative learning - CSCL '99, 1999
Reviewing past events has been useful in many domains. Videotapes and flight data recorders provi... more Reviewing past events has been useful in many domains. Videotapes and flight data recorders provide invaluable technological help to sports coaches or aviation engineers. Similarly, providing learners with a readable recording of their actions may help them monitor their behavior, reflect on their progress, and experiment with revisions of their experiences. It may also facilitate active collaboration among dispersed learning communities. Learning histories can help students and professionals make more effective use of digital library searching, word processing tasks, computer-assisted design tools, electronic performance support systems, and web navigation.
NATO Science for Peace and Security Series B: Physics and Biophysics, 2010
E. Gusev et al. (eds.), Advanced Materials and Technologies for Micro/Nano-Devices, ... Sensors a... more E. Gusev et al. (eds.), Advanced Materials and Technologies for Micro/Nano-Devices, ... Sensors and Actuators, DOI 10.1007/978-90-481-3807-4_22, © Springer Science + Business Media BV 2010 ... REZA GHODSSI1,*, PETER DYKSTRA1, MARIANA MEYER2, STEPHAN ...
IFMBE Proceedings, 2010
ABSTRACT
IFMBE Proceedings, 2010
ABSTRACT
IFMBE Proceedings, 2010
ABSTRACT