Sara Stolyarova - Academia.edu (original) (raw)
Papers by Sara Stolyarova
IEEE Transactions on Electron Devices, 2018
A new generation of thermal sensors based on a suspended thermal transistor MOS (TMOS), fabricate... more A new generation of thermal sensors based on a suspended thermal transistor MOS (TMOS), fabricated in the standard CMOS-SOI process, released by postetching, has been recently developed. One of the important features of TMOS is its high responsivity due to the transistor built-in amplification and subthreshold operation enabling a wide range of battery applications. This paper focuses on a new gas sensor, dubbed GMOS, based on the TMOS. The GMOS is a catalytic gas sensor (pellistor-like), and as such detects combustible gases in air. The CMOS-SOI technology combined with tungsten metallization enables operation at very high temperatures (450°C was tested). The sensors and readout are processed with the same CMOS-SOI technology. Accordingly, the GMOS sensor, processed in low-cost CMOS-SOI technology, promises to become the widely accepted gas sensing approach for mobile applications, including wearables, smart homes, as well as smartphones.
physica status solidi (b), 2002
Polycrystalline films of Cd 1-x Zn x Te (0 < x < 1) of 0.1 mm thickness on glass substrates were ... more Polycrystalline films of Cd 1-x Zn x Te (0 < x < 1) of 0.1 mm thickness on glass substrates were grown by Metal Organic Chemical Vapor Deposition at 480 C. X-ray diffraction and transmission electron microscopy (TEM) methods were used for the film characterization. TEM in-situ heating the Cd 1-x Zn x Te films in the range of 200 to 300 C caused the following structure transformations: strong recrystallization, twinning, and partial decomposition. The self-diffusion coefficient, as estimated by TEM in-situ recrystallization monitoring at 300 C was found to be on the order of 10-8 cm 2 /s. A CuPt-type superstructure grew spontaneously in the films during the film annealing.
physica status solidi (a), 2003
ABSTRACT
Journal of Crystal Growth, 1999
This work reports for the first time the preparation of ordered Cd \V Zn V Te epilayers. The epil... more This work reports for the first time the preparation of ordered Cd \V Zn V Te epilayers. The epilayers were deposited on CdTe (1 0 0) substrates by metal organic chemical vapor deposition in a horizontal quartz reactor. Diethylzinc, dimethylcadmuim and diethyltelluride were used as metalorganic precursors with hydrogen as a carrier gas. Influence of different growth parameters on the growth process is studied for the deposited Cd \V Zn V Te layers. Transmission electron microscopy diffraction was performed and the long-range ordering effect was observed for the first time, in these layers.
IEEE Transactions on Electron Devices, 2009
This paper reports the design, fabrication technology, post-CMOS micromachining and characterizat... more This paper reports the design, fabrication technology, post-CMOS micromachining and characterization of CMOS-silicon-on-insulator (SOI)-microelectromechanical system (MEMS) transistors. The thermally isolated micromachined CMOS-SOI-MEMS transistor reported here is designed for uncooled infrared (IR) sensing and is dubbed here as "TMOS." The measured dc and noise electrical characteristics of the asprocessed (virgin) transistor as well as those of the post-CMOS-MEMS-processed transistor (TMOS) are reported and compared. In particular, the threshold voltage temperature dependence and the temperature coefficient of current (TCC) at subthreshold are reported. The results indicate that the post-CMOS-MEMS processing does not degrade the performance of the transistors. The electrooptical performance of the TMOS is characterized and reported. With TCC on the order of 4%-10%, depending on the gate voltage, responsivity of 40 mA/W, noise equivalent power on the order of several tens of picowatts, and calculated noise equivalent temperature difference on the order of 64 mK, this uncooled IR sensor in standard CMOS-SOI technology may provide a high performance at a lower cost compared to state-of-the-art uncooled sensors based on bolometers implemented in non-CMOS materials like vanadium oxide or amorphous silicon.
physica status solidi (c), 2005
ABSTRACT
2017 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2017
This paper presents the performance of CMOS-SOI TMOS thermal sensor processed in a well-establish... more This paper presents the performance of CMOS-SOI TMOS thermal sensor processed in a well-established 1μm technology, operating in air. The TMOS is a micro-machined CMOS transistor, operating at subthreshold. The thermally isolated floating MOS transistor senses temperature changes induced by either a physical or a chemical phenomenon. The change in temperature modifies the threshold voltage and accordingly the I-V characteristics of the micro-machined transistor. Operation in air, without vacuum packaging, enables low-cost products for a wide range of low-cost commercial mobile applications such as IoT, wearables, smart homes and smartphones.
Micromachines, 2020
This is a second part of the paper presenting a miniature, combustion-type gas sensor (dubbed GMO... more This is a second part of the paper presenting a miniature, combustion-type gas sensor (dubbed GMOS) based on a novel thermal sensor (dubbed TMOS). The TMOS is a micromachined CMOS-SOI transistor, which acts as the sensing element and is integrated with a catalytic reaction plate, where ignition of the gas takes place. Part 1 focused on the chemical and technological aspects of the sensor. In part 2, the emphasis is on the physical aspects of the reaction micro-hot plate on which the catalytic layer is deposited. The three main challenges in designing the hot plate are addressed: (i) How to design a hot plate operating in air, with a low thermal conductivity; (ii) how to measure the temperature of the hot plate during operation; (iii) how to reduce the total consumed power during operation. Reported simulated as well as analytical models and measured results are in good agreement.
Journal of Crystal Growth, 2012
ABSTRACT In this paper, phenomena of enhanced nucleation and crystallization of biological and in... more ABSTRACT In this paper, phenomena of enhanced nucleation and crystallization of biological and inorganic materials on porous silicon (PS) are reviewed and explained using a microscopic approach accounting for the size and shape of individual pores. The facilitation of crystallization on PS is explained by the decrease of the potential barrier of nucleation, related to the decrease of the critical nucleus volume at heterogeneous nucleation in pores. For fractal surfaces, this decrease results in spontaneous solidification under minimal total supersaturation due to the wide distribution of pore sizes.
Journal of Physics D: Applied Physics, 1999
We report the evidence of long-range order (LRO) in CdZnTe epilayers grown by metal organic chemi... more We report the evidence of long-range order (LRO) in CdZnTe epilayers grown by metal organic chemical vapour deposition (MOCVD) on (100) CdTe. LRO has been characterized by both transmission electron microscopy (TEM) and polarized photoluminescence (PL) measurements. The observation of extra-spots in the diffraction pattern of Cd0.52 Zn0.48 Te samples indicate the CuPt type structure, as corroborated by computer simulation. Valence band splitting (VBS) up to 25 meV, measured by polarized PL gives additional proof of atomic ordering. The order parameter icons/Journals/Common/eta" ALT="eta" ALIGN="TOP"/> = 0.6 was calculated from VBS using a parabolic approximation.
7th International Electronic Conference on Sensors and Applications, 2020
2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2019
This paper focuses on the thermal performance of a wafer level packaged MEMS thermal sensor, wher... more This paper focuses on the thermal performance of a wafer level packaged MEMS thermal sensor, where the pressure varies between deep vacuum (0.1 Pa) and atmospheric pressure. The simulations are based on commercial software and are corroborated by modeling and measurements. There is a good agreement between the measured experimental data for the thermal time constant and the modeling and simulations.
This paper presents a miniaturized catalytic gas sensor (Pellistor-like; dubbed GMOS) where the t... more This paper presents a miniaturized catalytic gas sensor (Pellistor-like; dubbed GMOS) where the thermal sensor is a micromachined CMOS -SOI transistor upon which nano particles of Pt are printed. The printing technology and equipment as well as the Pt ink suitable for printing on wafer scale, are described. The enhanced performance compared to sputtered Pt thin layer is reported. The GMOS sensor, processed in low cost CMOS-SOI technology, and wafer level processing and packaging promises to become the widely accepted gas sensing approach for mobile applications, including wearables, smart homes as well as smart phones.
Engineering Proceedings, 2020
Wafer-level processed and wafer-level packaged low-cost microelectromechanical system (MEMS) ther... more Wafer-level processed and wafer-level packaged low-cost microelectromechanical system (MEMS) thermal sensors are required for a wide range of Internet of Things (IoT) and wearables applications. Recently, a new generation of uncooled thermal sensors based on CMOS-SOI-MEMS technology has emerged, with higher performance compared to commercial thermal sensors (bolometers, thermopiles, and pyroelectric sensors). The technology is implemented in commercial CMOS FABs and is, therefore, based on mature technology and implemented at a low cost. When packaged in a high vacuum, the sensors are dubbed TMOS and are applied for uncooled IR radiation. At atmospheric pressure, the sensors may function as gas sensors, dubbed GMOS. This paper focuses on the study of the thermal performance of wafer-level processed and packaged TMOS and GMOS sensors, where the pressure varies between high vacuum (0.01 Pa) and atmospheric pressure. The present study is based on analytical thermal modeling for gaining...
Micromachines, 2020
There is an ongoing effort to fabricate miniature, low cost, sensitive, and selective gas sensors... more There is an ongoing effort to fabricate miniature, low cost, sensitive, and selective gas sensors for domestic and industrial uses. This paper presents a miniature combustion-type gas sensor (GMOS) based on a thermal sensor, where a micromachined CMOS–SOI transistor integrated with a catalytic reaction plate acts as a sensing element. This study emphasizes GMOS performance modeling, technological aspects, and sensing-selectivity issues. Two deposition techniques of a Pt catalytic layer suitable for wafer-level processing were compared, magnetron sputtering and nanoparticle inkjet printing. Both techniques have been useful for the fabrication of GMOS sensor, with good sensitivity to ethanol and acetone in the air. However, a printed Pt nanoparticle catalyst provides almost twice as much sensitivity as compared to that of the sputtered catalyst. Moreover, sensing selectivity in the ethanol/acetone gas mixture was demonstrated for the GMOS with a Pt nanoparticle catalyst. These advanta...
MRS Proceedings, 2003
Direct integration of sol-gel derived ceramic films with porous silicon, without buffer layers, h... more Direct integration of sol-gel derived ceramic films with porous silicon, without buffer layers, has been demonstrated. The effects of ceramic type, solvent type, solution concentration, as well as, porous silicon layer thickness, porosity and preparation conditions, on the quality and microstructure of sol-gel films/porous silicon integrated systems have been studied. The following ceramic compositions have been applied to porous silicon as protective coatings: PZT (PbZr0.3Ti0.7O3), PLZT (Pb0.925La0.055Zr0.3Ti0.7O3), ZrO2, TiO2, with 2-methoxyethanol and 2-ethoxyethanol solvents, 0.5 and 0.1 M precursor solution concentrations. The LSCO (La0.5Sr0.5CO.3) water based sol-gels have been deposited for electroconductive purposes.The best compositions for integration, giving transparent, mirror-like, uniform ceramic films with fine morphology and strong adhesion, were found to be the TiO2 and ZrO2 as well as, the diluted (0.1 M) PZT (PbZr0.3Ti0.7O3) sol-gel precursors. Conductive LSCO sol...
2012 International Conference on Optical MEMS and Nanophotonics, 2012
ABSTRACT We report a novel THz sensor, based on several leading technologies: THz photonics, CMOS... more ABSTRACT We report a novel THz sensor, based on several leading technologies: THz photonics, CMOS-SOI and NEMS. By integrating the TeraMOS sensor with “thermal antenna”, we expect to achieve a breakthrough in uncooled Terahertz passive imaging.
physica status solidi (a), 2002
IEEE Transactions on Electron Devices, 2018
A new generation of thermal sensors based on a suspended thermal transistor MOS (TMOS), fabricate... more A new generation of thermal sensors based on a suspended thermal transistor MOS (TMOS), fabricated in the standard CMOS-SOI process, released by postetching, has been recently developed. One of the important features of TMOS is its high responsivity due to the transistor built-in amplification and subthreshold operation enabling a wide range of battery applications. This paper focuses on a new gas sensor, dubbed GMOS, based on the TMOS. The GMOS is a catalytic gas sensor (pellistor-like), and as such detects combustible gases in air. The CMOS-SOI technology combined with tungsten metallization enables operation at very high temperatures (450°C was tested). The sensors and readout are processed with the same CMOS-SOI technology. Accordingly, the GMOS sensor, processed in low-cost CMOS-SOI technology, promises to become the widely accepted gas sensing approach for mobile applications, including wearables, smart homes, as well as smartphones.
physica status solidi (b), 2002
Polycrystalline films of Cd 1-x Zn x Te (0 < x < 1) of 0.1 mm thickness on glass substrates were ... more Polycrystalline films of Cd 1-x Zn x Te (0 < x < 1) of 0.1 mm thickness on glass substrates were grown by Metal Organic Chemical Vapor Deposition at 480 C. X-ray diffraction and transmission electron microscopy (TEM) methods were used for the film characterization. TEM in-situ heating the Cd 1-x Zn x Te films in the range of 200 to 300 C caused the following structure transformations: strong recrystallization, twinning, and partial decomposition. The self-diffusion coefficient, as estimated by TEM in-situ recrystallization monitoring at 300 C was found to be on the order of 10-8 cm 2 /s. A CuPt-type superstructure grew spontaneously in the films during the film annealing.
physica status solidi (a), 2003
ABSTRACT
Journal of Crystal Growth, 1999
This work reports for the first time the preparation of ordered Cd \V Zn V Te epilayers. The epil... more This work reports for the first time the preparation of ordered Cd \V Zn V Te epilayers. The epilayers were deposited on CdTe (1 0 0) substrates by metal organic chemical vapor deposition in a horizontal quartz reactor. Diethylzinc, dimethylcadmuim and diethyltelluride were used as metalorganic precursors with hydrogen as a carrier gas. Influence of different growth parameters on the growth process is studied for the deposited Cd \V Zn V Te layers. Transmission electron microscopy diffraction was performed and the long-range ordering effect was observed for the first time, in these layers.
IEEE Transactions on Electron Devices, 2009
This paper reports the design, fabrication technology, post-CMOS micromachining and characterizat... more This paper reports the design, fabrication technology, post-CMOS micromachining and characterization of CMOS-silicon-on-insulator (SOI)-microelectromechanical system (MEMS) transistors. The thermally isolated micromachined CMOS-SOI-MEMS transistor reported here is designed for uncooled infrared (IR) sensing and is dubbed here as "TMOS." The measured dc and noise electrical characteristics of the asprocessed (virgin) transistor as well as those of the post-CMOS-MEMS-processed transistor (TMOS) are reported and compared. In particular, the threshold voltage temperature dependence and the temperature coefficient of current (TCC) at subthreshold are reported. The results indicate that the post-CMOS-MEMS processing does not degrade the performance of the transistors. The electrooptical performance of the TMOS is characterized and reported. With TCC on the order of 4%-10%, depending on the gate voltage, responsivity of 40 mA/W, noise equivalent power on the order of several tens of picowatts, and calculated noise equivalent temperature difference on the order of 64 mK, this uncooled IR sensor in standard CMOS-SOI technology may provide a high performance at a lower cost compared to state-of-the-art uncooled sensors based on bolometers implemented in non-CMOS materials like vanadium oxide or amorphous silicon.
physica status solidi (c), 2005
ABSTRACT
2017 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2017
This paper presents the performance of CMOS-SOI TMOS thermal sensor processed in a well-establish... more This paper presents the performance of CMOS-SOI TMOS thermal sensor processed in a well-established 1μm technology, operating in air. The TMOS is a micro-machined CMOS transistor, operating at subthreshold. The thermally isolated floating MOS transistor senses temperature changes induced by either a physical or a chemical phenomenon. The change in temperature modifies the threshold voltage and accordingly the I-V characteristics of the micro-machined transistor. Operation in air, without vacuum packaging, enables low-cost products for a wide range of low-cost commercial mobile applications such as IoT, wearables, smart homes and smartphones.
Micromachines, 2020
This is a second part of the paper presenting a miniature, combustion-type gas sensor (dubbed GMO... more This is a second part of the paper presenting a miniature, combustion-type gas sensor (dubbed GMOS) based on a novel thermal sensor (dubbed TMOS). The TMOS is a micromachined CMOS-SOI transistor, which acts as the sensing element and is integrated with a catalytic reaction plate, where ignition of the gas takes place. Part 1 focused on the chemical and technological aspects of the sensor. In part 2, the emphasis is on the physical aspects of the reaction micro-hot plate on which the catalytic layer is deposited. The three main challenges in designing the hot plate are addressed: (i) How to design a hot plate operating in air, with a low thermal conductivity; (ii) how to measure the temperature of the hot plate during operation; (iii) how to reduce the total consumed power during operation. Reported simulated as well as analytical models and measured results are in good agreement.
Journal of Crystal Growth, 2012
ABSTRACT In this paper, phenomena of enhanced nucleation and crystallization of biological and in... more ABSTRACT In this paper, phenomena of enhanced nucleation and crystallization of biological and inorganic materials on porous silicon (PS) are reviewed and explained using a microscopic approach accounting for the size and shape of individual pores. The facilitation of crystallization on PS is explained by the decrease of the potential barrier of nucleation, related to the decrease of the critical nucleus volume at heterogeneous nucleation in pores. For fractal surfaces, this decrease results in spontaneous solidification under minimal total supersaturation due to the wide distribution of pore sizes.
Journal of Physics D: Applied Physics, 1999
We report the evidence of long-range order (LRO) in CdZnTe epilayers grown by metal organic chemi... more We report the evidence of long-range order (LRO) in CdZnTe epilayers grown by metal organic chemical vapour deposition (MOCVD) on (100) CdTe. LRO has been characterized by both transmission electron microscopy (TEM) and polarized photoluminescence (PL) measurements. The observation of extra-spots in the diffraction pattern of Cd0.52 Zn0.48 Te samples indicate the CuPt type structure, as corroborated by computer simulation. Valence band splitting (VBS) up to 25 meV, measured by polarized PL gives additional proof of atomic ordering. The order parameter icons/Journals/Common/eta" ALT="eta" ALIGN="TOP"/> = 0.6 was calculated from VBS using a parabolic approximation.
7th International Electronic Conference on Sensors and Applications, 2020
2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2019
This paper focuses on the thermal performance of a wafer level packaged MEMS thermal sensor, wher... more This paper focuses on the thermal performance of a wafer level packaged MEMS thermal sensor, where the pressure varies between deep vacuum (0.1 Pa) and atmospheric pressure. The simulations are based on commercial software and are corroborated by modeling and measurements. There is a good agreement between the measured experimental data for the thermal time constant and the modeling and simulations.
This paper presents a miniaturized catalytic gas sensor (Pellistor-like; dubbed GMOS) where the t... more This paper presents a miniaturized catalytic gas sensor (Pellistor-like; dubbed GMOS) where the thermal sensor is a micromachined CMOS -SOI transistor upon which nano particles of Pt are printed. The printing technology and equipment as well as the Pt ink suitable for printing on wafer scale, are described. The enhanced performance compared to sputtered Pt thin layer is reported. The GMOS sensor, processed in low cost CMOS-SOI technology, and wafer level processing and packaging promises to become the widely accepted gas sensing approach for mobile applications, including wearables, smart homes as well as smart phones.
Engineering Proceedings, 2020
Wafer-level processed and wafer-level packaged low-cost microelectromechanical system (MEMS) ther... more Wafer-level processed and wafer-level packaged low-cost microelectromechanical system (MEMS) thermal sensors are required for a wide range of Internet of Things (IoT) and wearables applications. Recently, a new generation of uncooled thermal sensors based on CMOS-SOI-MEMS technology has emerged, with higher performance compared to commercial thermal sensors (bolometers, thermopiles, and pyroelectric sensors). The technology is implemented in commercial CMOS FABs and is, therefore, based on mature technology and implemented at a low cost. When packaged in a high vacuum, the sensors are dubbed TMOS and are applied for uncooled IR radiation. At atmospheric pressure, the sensors may function as gas sensors, dubbed GMOS. This paper focuses on the study of the thermal performance of wafer-level processed and packaged TMOS and GMOS sensors, where the pressure varies between high vacuum (0.01 Pa) and atmospheric pressure. The present study is based on analytical thermal modeling for gaining...
Micromachines, 2020
There is an ongoing effort to fabricate miniature, low cost, sensitive, and selective gas sensors... more There is an ongoing effort to fabricate miniature, low cost, sensitive, and selective gas sensors for domestic and industrial uses. This paper presents a miniature combustion-type gas sensor (GMOS) based on a thermal sensor, where a micromachined CMOS–SOI transistor integrated with a catalytic reaction plate acts as a sensing element. This study emphasizes GMOS performance modeling, technological aspects, and sensing-selectivity issues. Two deposition techniques of a Pt catalytic layer suitable for wafer-level processing were compared, magnetron sputtering and nanoparticle inkjet printing. Both techniques have been useful for the fabrication of GMOS sensor, with good sensitivity to ethanol and acetone in the air. However, a printed Pt nanoparticle catalyst provides almost twice as much sensitivity as compared to that of the sputtered catalyst. Moreover, sensing selectivity in the ethanol/acetone gas mixture was demonstrated for the GMOS with a Pt nanoparticle catalyst. These advanta...
MRS Proceedings, 2003
Direct integration of sol-gel derived ceramic films with porous silicon, without buffer layers, h... more Direct integration of sol-gel derived ceramic films with porous silicon, without buffer layers, has been demonstrated. The effects of ceramic type, solvent type, solution concentration, as well as, porous silicon layer thickness, porosity and preparation conditions, on the quality and microstructure of sol-gel films/porous silicon integrated systems have been studied. The following ceramic compositions have been applied to porous silicon as protective coatings: PZT (PbZr0.3Ti0.7O3), PLZT (Pb0.925La0.055Zr0.3Ti0.7O3), ZrO2, TiO2, with 2-methoxyethanol and 2-ethoxyethanol solvents, 0.5 and 0.1 M precursor solution concentrations. The LSCO (La0.5Sr0.5CO.3) water based sol-gels have been deposited for electroconductive purposes.The best compositions for integration, giving transparent, mirror-like, uniform ceramic films with fine morphology and strong adhesion, were found to be the TiO2 and ZrO2 as well as, the diluted (0.1 M) PZT (PbZr0.3Ti0.7O3) sol-gel precursors. Conductive LSCO sol...
2012 International Conference on Optical MEMS and Nanophotonics, 2012
ABSTRACT We report a novel THz sensor, based on several leading technologies: THz photonics, CMOS... more ABSTRACT We report a novel THz sensor, based on several leading technologies: THz photonics, CMOS-SOI and NEMS. By integrating the TeraMOS sensor with “thermal antenna”, we expect to achieve a breakthrough in uncooled Terahertz passive imaging.
physica status solidi (a), 2002