Michael DiBattista - Academia.edu (original) (raw)

Uploads

Papers by Michael DiBattista

2007 2nd International Workshop on Advances in Sensors and Interface, 2007

Olfactory receptors (ORs) comprise a large gene family (-1200 proteins encoded by OR genes) and t... more Olfactory receptors (ORs) comprise a large gene family (-1200 proteins encoded by OR genes) and thus are excellent candidates for the fabrication of sensitive biosensors for explosives and other chemicals of interest. Our research project aims to address these two fundamental questions: Which are the volatile components of landmines recognized specifically by animals? How do olfactory neurons located in their

Sensors and Actuators B: Chemical, 2001

The analysis of the in¯uence of deposition modes on the structure, electrical and gas sensitivity... more The analysis of the in¯uence of deposition modes on the structure, electrical and gas sensitivity characteristics of SnO 2 ®lms, deposited by spray pyrolysis, is presented in this report. X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser ellipsometry were used for this purpose. It was determined that nano-size polycrystalline SnO 2 ®lms with thickness >30 nm can have different structure in dependence on pyrolysis temperature and ®lm thickness. Ultra-thin SnO 2 ®lms with thickness d < 20 nm are discontinuous. The relation between structure of the ®lms and gas sensitivity properties is discussed. The explanation of observed effects was made. #

Sensors and Actuators B: Chemical, 1996

This investigation addresses the important question of whether or not silicon-based micromachined... more This investigation addresses the important question of whether or not silicon-based micromachined chemical sensors are a viable option for gas sensing in harsh, high-temperature flow applications such as automotive exhaust. Data are presented on the thermal and mechanical stability and long-term functionality of micromachined silicon devices containing ultra-thin Pt/TiOx films supported on a heated muitilayer silicon oxide/silicon nitride membrane. These gas detectors were originally designed for use in vacuum applications such as reactive ion etching systems. Significant modifications in device structure and materials are required to adapt these sensors for use in harsh thermal and chemical environments at elevated pressures. To test the long-term structural integrity of the sensors, they are subjected to a test protocol including pressure fluctuations, thermal shock, and mechanical vibrations. For characterization purposes, electrical resistance measurements, optical microscopy, atomic force microscopy (AFM), and Auger spectroscopy have been used. Our results indicate that properly designed micromachined silicon structures can survive long-term operation at high temperatures in ambient air, and can withstand rapid fluctuations of temperature, pressure, and flow rate.

Materials Science and Engineering: B, 2000

The results of SnO 2 thin film structure characterization using X-ray diffraction, scanning elect... more The results of SnO 2 thin film structure characterization using X-ray diffraction, scanning electron microscopy, and Auger electron spectroscopy are presented in this report. We discuss the influence of film deposition conditions and modes of heat treatment in the range of temperatures (400-900°C) on crystallite size and predominant orientation. It was determined that SnO 2 films, deposited by spray pyrolysis, are textured polycrystalline films. The crystallite sizes in the films could be controlled over a range from 9 to 25 nm by varying the film thickness, deposition method, and post-deposition annealing temperature. The structure of these SnO 2 films was very stable in an oxygen-containing atmosphere. It was found that crystallite orientation, in addition to crystallite size, plays a major role in determining the gas sensitivity of SnO 2 films. Crystallites with crystallographic (110) and (200) planes parallel to substrate are predominant in the films. The relative amounts of crystallites with a (110) and (200) orientation depend on film thickness and deposition mode.

Journal of Applied Physics, 1999

Grain boundary diffusion of titanium through platinum thin films has been carried out in the temp... more Grain boundary diffusion of titanium through platinum thin films has been carried out in the temperature range from 200 to 600°C. Five different platinum/titanium bilayer thicknesses, from 35 to 800 Å Pt, were annealed in 5% O 2 /95% N 2. The accumulation of titanium at the platinum surface layer was measured by x-ray photoelectron spectroscopy ͑XPS͒ to determine the grain boundary diffusion coefficient (D b). Diffusivity values were calculated based on two different analysis methods assuming type C kinetics. For Pt layers thicker than 200 Å, the activation energy (Q b) for titanium diffusion was found to be 118Ϯ15 kJ/mol ͑1.22Ϯ0.16 eV͒. For Pt layers thinner than 200 Å, there was a thickness dependence on the diffusion kinetics, resulting in activation energies as low as 20Ϯ4 kJ/mol ͑0.21Ϯ0.04 eV͒. XPS results gave no evidence for any Pt-Ti alloy formation in these layers. The suppression of alloy formation may be attributed to the presence of oxygen at the Pt/Ti interface during layer deposition. The quantitative analysis of titanium interdiffusion in platinum provides valuable information regarding Pt/Ti surface concentrations in thin-film chemical sensors, and for understanding changes in operational characteristics of platinum electrodes.

Electron Devices …, 2005

Erratic bit phenomena have been reported in advanced flash memories, and have been attributed to ... more Erratic bit phenomena have been reported in advanced flash memories, and have been attributed to trapping/detrapping effects that modify the threshold voltage. This paper describes for the first time the observance of erratic behavior in SRAM Vmin, defined as the minimum voltage at ...

Applied Surface Science, 1999

. A microfabricated hot stage for a scanning probe microscope SPM has been developed to enable in... more . A microfabricated hot stage for a scanning probe microscope SPM has been developed to enable in-situ investigations of thin film specimens at elevated temperatures. With this hot stage, a SPM can now examine and test materials at high magnifications under conditions that closely resemble their true service temperature. The hot stage is capable of operating from ambient room temperature up to 8008C without damage to the microscope. With this device, topographical images of platinum supported titanium films, which are important for catalytic reaction studies, thin film gas sensor technology, and microelectronic applications, have been acquired at temperatures between 25-4008C. The average roughness of these films remained constant at 12.4 " 1.9 nm. The surface of the hot stage can be equipped with electrodes enabling four point probe measurements of conducting specimens as the temperature is increased and the surface is imaged. In-situ imaging of the titanium underlayer diffusing through the platinum film has been observed at 3758C. Titanium migration to the surface near˚Ž . this temperature is also shown on 35 A Ptr65 A Ti films with X-ray photoelectron spectroscopy XPS . This stage can be retrofitted to any existing SPM to expand its current capabilities to include high temperature analysis of a wide diversity of materials, from biological samples, to polymers, and metals. q

2007 2nd International Workshop on Advances in Sensors and Interface, 2007

Olfactory receptors (ORs) comprise a large gene family (-1200 proteins encoded by OR genes) and t... more Olfactory receptors (ORs) comprise a large gene family (-1200 proteins encoded by OR genes) and thus are excellent candidates for the fabrication of sensitive biosensors for explosives and other chemicals of interest. Our research project aims to address these two fundamental questions: Which are the volatile components of landmines recognized specifically by animals? How do olfactory neurons located in their

Sensors and Actuators B: Chemical, 2001

The analysis of the in¯uence of deposition modes on the structure, electrical and gas sensitivity... more The analysis of the in¯uence of deposition modes on the structure, electrical and gas sensitivity characteristics of SnO 2 ®lms, deposited by spray pyrolysis, is presented in this report. X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser ellipsometry were used for this purpose. It was determined that nano-size polycrystalline SnO 2 ®lms with thickness >30 nm can have different structure in dependence on pyrolysis temperature and ®lm thickness. Ultra-thin SnO 2 ®lms with thickness d < 20 nm are discontinuous. The relation between structure of the ®lms and gas sensitivity properties is discussed. The explanation of observed effects was made. #

Sensors and Actuators B: Chemical, 1996

This investigation addresses the important question of whether or not silicon-based micromachined... more This investigation addresses the important question of whether or not silicon-based micromachined chemical sensors are a viable option for gas sensing in harsh, high-temperature flow applications such as automotive exhaust. Data are presented on the thermal and mechanical stability and long-term functionality of micromachined silicon devices containing ultra-thin Pt/TiOx films supported on a heated muitilayer silicon oxide/silicon nitride membrane. These gas detectors were originally designed for use in vacuum applications such as reactive ion etching systems. Significant modifications in device structure and materials are required to adapt these sensors for use in harsh thermal and chemical environments at elevated pressures. To test the long-term structural integrity of the sensors, they are subjected to a test protocol including pressure fluctuations, thermal shock, and mechanical vibrations. For characterization purposes, electrical resistance measurements, optical microscopy, atomic force microscopy (AFM), and Auger spectroscopy have been used. Our results indicate that properly designed micromachined silicon structures can survive long-term operation at high temperatures in ambient air, and can withstand rapid fluctuations of temperature, pressure, and flow rate.

Materials Science and Engineering: B, 2000

The results of SnO 2 thin film structure characterization using X-ray diffraction, scanning elect... more The results of SnO 2 thin film structure characterization using X-ray diffraction, scanning electron microscopy, and Auger electron spectroscopy are presented in this report. We discuss the influence of film deposition conditions and modes of heat treatment in the range of temperatures (400-900°C) on crystallite size and predominant orientation. It was determined that SnO 2 films, deposited by spray pyrolysis, are textured polycrystalline films. The crystallite sizes in the films could be controlled over a range from 9 to 25 nm by varying the film thickness, deposition method, and post-deposition annealing temperature. The structure of these SnO 2 films was very stable in an oxygen-containing atmosphere. It was found that crystallite orientation, in addition to crystallite size, plays a major role in determining the gas sensitivity of SnO 2 films. Crystallites with crystallographic (110) and (200) planes parallel to substrate are predominant in the films. The relative amounts of crystallites with a (110) and (200) orientation depend on film thickness and deposition mode.

Journal of Applied Physics, 1999

Grain boundary diffusion of titanium through platinum thin films has been carried out in the temp... more Grain boundary diffusion of titanium through platinum thin films has been carried out in the temperature range from 200 to 600°C. Five different platinum/titanium bilayer thicknesses, from 35 to 800 Å Pt, were annealed in 5% O 2 /95% N 2. The accumulation of titanium at the platinum surface layer was measured by x-ray photoelectron spectroscopy ͑XPS͒ to determine the grain boundary diffusion coefficient (D b). Diffusivity values were calculated based on two different analysis methods assuming type C kinetics. For Pt layers thicker than 200 Å, the activation energy (Q b) for titanium diffusion was found to be 118Ϯ15 kJ/mol ͑1.22Ϯ0.16 eV͒. For Pt layers thinner than 200 Å, there was a thickness dependence on the diffusion kinetics, resulting in activation energies as low as 20Ϯ4 kJ/mol ͑0.21Ϯ0.04 eV͒. XPS results gave no evidence for any Pt-Ti alloy formation in these layers. The suppression of alloy formation may be attributed to the presence of oxygen at the Pt/Ti interface during layer deposition. The quantitative analysis of titanium interdiffusion in platinum provides valuable information regarding Pt/Ti surface concentrations in thin-film chemical sensors, and for understanding changes in operational characteristics of platinum electrodes.

Electron Devices …, 2005

Erratic bit phenomena have been reported in advanced flash memories, and have been attributed to ... more Erratic bit phenomena have been reported in advanced flash memories, and have been attributed to trapping/detrapping effects that modify the threshold voltage. This paper describes for the first time the observance of erratic behavior in SRAM Vmin, defined as the minimum voltage at ...

Applied Surface Science, 1999

. A microfabricated hot stage for a scanning probe microscope SPM has been developed to enable in... more . A microfabricated hot stage for a scanning probe microscope SPM has been developed to enable in-situ investigations of thin film specimens at elevated temperatures. With this hot stage, a SPM can now examine and test materials at high magnifications under conditions that closely resemble their true service temperature. The hot stage is capable of operating from ambient room temperature up to 8008C without damage to the microscope. With this device, topographical images of platinum supported titanium films, which are important for catalytic reaction studies, thin film gas sensor technology, and microelectronic applications, have been acquired at temperatures between 25-4008C. The average roughness of these films remained constant at 12.4 " 1.9 nm. The surface of the hot stage can be equipped with electrodes enabling four point probe measurements of conducting specimens as the temperature is increased and the surface is imaged. In-situ imaging of the titanium underlayer diffusing through the platinum film has been observed at 3758C. Titanium migration to the surface near˚Ž . this temperature is also shown on 35 A Ptr65 A Ti films with X-ray photoelectron spectroscopy XPS . This stage can be retrofitted to any existing SPM to expand its current capabilities to include high temperature analysis of a wide diversity of materials, from biological samples, to polymers, and metals. q