In this paper, we report measurements of electron effective mobility (μeff) in ultra-thin (UT) pu... more In this paper, we report measurements of electron effective mobility (μeff) in ultra-thin (UT) pure SiO2 bulk MOSFETs. A low substrate doping was intentionally used to better detect a possible μeff degradation at small Tox. New quantitative criteria were developed and used to obtain μeff measurements unaffected by either gate doping penetration or gate oxide leakage. Mobility simulations, based on
Scattering nanoparticles of Au and Ag have been shown to provide absorption enhancements in solar... more Scattering nanoparticles of Au and Ag have been shown to provide absorption enhancements in solar cells at wavelengths longer than ~550 nm. However these systems typically suffer from losses at short wavelengths due to parasitic absorption in the metal. In this paper we show that the choice of scattering material is crucial to minimize parasitic losses and achieve broadband absorption enhancements. To this end we present the results of an experimental comparison of GaAs photodiodes with periodic arrays of Au, Ag and Al nanoparticles fabricated on the front surface. In particular, we demonstrate that by using Al nanoparticle arrays the optical absorption can be enhanced across a spectral range from 400 – 900 nm leading to an integrated external quantum efficiency enhancement of more than 20 %. Our results are supported by comprehensive 3D electromagnetic and electrical simulations that provide an insight into the underlying physics, demonstrating that the electric field penetration into Al is significantly lower than that of Au and Ag, hence reducing parasitic absorption.
Integration of microelectronics with microfluidics enables sophisticated lab-on-a-chip devices fo... more Integration of microelectronics with microfluidics enables sophisticated lab-on-a-chip devices for sensing and actuation. In this paper, we investigate a novel method for in-situ microfluidics fabrication and packaging on wafer level. Two novel photo-patternable adhesive polymers were tested and compared, PA-S500H and DXL-009. The microfluidics fabrication method employs photo lithographical patterning of spin coated polymer films of PA or DXL and direct bonding of formed microfluidics to a top glass cover using die-to-wafer level bonding. These new adhesive materials remove the need for additional gluing layers. With this approach, we fabricated disposable microfluidic flow cytometers and evaluated the performance of those materials in the context of this application. DXL-009 exhibits lower autofluorescence compared to PA-S500H which improves detection sensitivity of fluorescently stained cells. Results obtained from the cytotoxicity test reveals that both materials are biocompatib...
High rate and safe cell sorting is enabled by rapid thermal bubble jet flow in a closed microflui... more High rate and safe cell sorting is enabled by rapid thermal bubble jet flow in a closed microfluidic chip.
We investigate how an array of nanoparticles embedded in the anti-reflection coating can improve ... more We investigate how an array of nanoparticles embedded in the anti-reflection coating can improve the radiation hardness of multi-junction space solar cells. In space, high-energy electron and proton radiation reduces solar cell efficiency. Most notably, the InGaAs-middle-cell diffusion lengths are degraded, reducing photocurrent. Metal nanoparticles can scatter incident photons obliquely into the semiconductor, reducing their penetration depths and hence causing charge carriers to be photogenerated closer to the junctions. We postulate that this can improve radiation hardness by improving carrier collection at end of life. In this work, GaInP/InGaAs/Ge solar cells with optimised double-layer AlOx/TiOx ARCs were fabricated with regular arrays of Al nanoparticles deposited on top. An electro-optical simulation tool was also developed, and validated by comparison to the measured quantum efficiency and reflectance spectra, with good agreement. Using the validated simulation tool, we predict the photocurrent before and after high energy electron irradiation. The fraction of the initial photocurrent remaining after irradiation is predicted to improve for certain nanoparticle arrays. However, the overall photocurrent both before and after irradiation is reduced by the presence of the particles. Hence a net benefit is not predicted for the studied array dimensions.
Electrical Performance of Electrical Packaging (IEEE Cat. No. 03TH8710)
ABSTRACT A CMOS process is developed in a research environment for integration studies of sub-50 ... more ABSTRACT A CMOS process is developed in a research environment for integration studies of sub-50 nm MOSFETs with high-k (HiK) dielectrics, metal gates (MG), ultra-shallow junctions with laser thermal annealing (LTA), raised source/drain (RSD) and novel device architectures (e.g., double-gate transistors, strained channels). We have optimized the process parameters and show that high-performance transistors can be realized, promising direct applicability of the results to future manufacturing.
In this paper, a FinFLASH memory device is presented using hot carrier program/erase modes. For 2... more In this paper, a FinFLASH memory device is presented using hot carrier program/erase modes. For 2 bits/cell operation, we show that multi-level charge sensing should be preferred over two physical bits/cell storage. While the dual-bit reading scheme limits the later to about 1 V operating window, multilevel solution is demonstrated with a total window of 6 V. This allows the
In this paper, we report measurements of electron effective mobility (μeff) in ultra-thin (UT) pu... more In this paper, we report measurements of electron effective mobility (μeff) in ultra-thin (UT) pure SiO2 bulk MOSFETs. A low substrate doping was intentionally used to better detect a possible μeff degradation at small Tox. New quantitative criteria were developed and used to obtain μeff measurements unaffected by either gate doping penetration or gate oxide leakage. Mobility simulations, based on
Scattering nanoparticles of Au and Ag have been shown to provide absorption enhancements in solar... more Scattering nanoparticles of Au and Ag have been shown to provide absorption enhancements in solar cells at wavelengths longer than ~550 nm. However these systems typically suffer from losses at short wavelengths due to parasitic absorption in the metal. In this paper we show that the choice of scattering material is crucial to minimize parasitic losses and achieve broadband absorption enhancements. To this end we present the results of an experimental comparison of GaAs photodiodes with periodic arrays of Au, Ag and Al nanoparticles fabricated on the front surface. In particular, we demonstrate that by using Al nanoparticle arrays the optical absorption can be enhanced across a spectral range from 400 – 900 nm leading to an integrated external quantum efficiency enhancement of more than 20 %. Our results are supported by comprehensive 3D electromagnetic and electrical simulations that provide an insight into the underlying physics, demonstrating that the electric field penetration into Al is significantly lower than that of Au and Ag, hence reducing parasitic absorption.
Integration of microelectronics with microfluidics enables sophisticated lab-on-a-chip devices fo... more Integration of microelectronics with microfluidics enables sophisticated lab-on-a-chip devices for sensing and actuation. In this paper, we investigate a novel method for in-situ microfluidics fabrication and packaging on wafer level. Two novel photo-patternable adhesive polymers were tested and compared, PA-S500H and DXL-009. The microfluidics fabrication method employs photo lithographical patterning of spin coated polymer films of PA or DXL and direct bonding of formed microfluidics to a top glass cover using die-to-wafer level bonding. These new adhesive materials remove the need for additional gluing layers. With this approach, we fabricated disposable microfluidic flow cytometers and evaluated the performance of those materials in the context of this application. DXL-009 exhibits lower autofluorescence compared to PA-S500H which improves detection sensitivity of fluorescently stained cells. Results obtained from the cytotoxicity test reveals that both materials are biocompatib...
High rate and safe cell sorting is enabled by rapid thermal bubble jet flow in a closed microflui... more High rate and safe cell sorting is enabled by rapid thermal bubble jet flow in a closed microfluidic chip.
We investigate how an array of nanoparticles embedded in the anti-reflection coating can improve ... more We investigate how an array of nanoparticles embedded in the anti-reflection coating can improve the radiation hardness of multi-junction space solar cells. In space, high-energy electron and proton radiation reduces solar cell efficiency. Most notably, the InGaAs-middle-cell diffusion lengths are degraded, reducing photocurrent. Metal nanoparticles can scatter incident photons obliquely into the semiconductor, reducing their penetration depths and hence causing charge carriers to be photogenerated closer to the junctions. We postulate that this can improve radiation hardness by improving carrier collection at end of life. In this work, GaInP/InGaAs/Ge solar cells with optimised double-layer AlOx/TiOx ARCs were fabricated with regular arrays of Al nanoparticles deposited on top. An electro-optical simulation tool was also developed, and validated by comparison to the measured quantum efficiency and reflectance spectra, with good agreement. Using the validated simulation tool, we predict the photocurrent before and after high energy electron irradiation. The fraction of the initial photocurrent remaining after irradiation is predicted to improve for certain nanoparticle arrays. However, the overall photocurrent both before and after irradiation is reduced by the presence of the particles. Hence a net benefit is not predicted for the studied array dimensions.
Electrical Performance of Electrical Packaging (IEEE Cat. No. 03TH8710)
ABSTRACT A CMOS process is developed in a research environment for integration studies of sub-50 ... more ABSTRACT A CMOS process is developed in a research environment for integration studies of sub-50 nm MOSFETs with high-k (HiK) dielectrics, metal gates (MG), ultra-shallow junctions with laser thermal annealing (LTA), raised source/drain (RSD) and novel device architectures (e.g., double-gate transistors, strained channels). We have optimized the process parameters and show that high-performance transistors can be realized, promising direct applicability of the results to future manufacturing.
In this paper, a FinFLASH memory device is presented using hot carrier program/erase modes. For 2... more In this paper, a FinFLASH memory device is presented using hot carrier program/erase modes. For 2 bits/cell operation, we show that multi-level charge sensing should be preferred over two physical bits/cell storage. While the dual-bit reading scheme limits the later to about 1 V operating window, multilevel solution is demonstrated with a total window of 6 V. This allows the
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Papers by Josine Loo