Search results for "SILICON"
showing 10 items of 1391 documents
CCDC 1995923: Experimental Crystal Structure Determination
2020
Related Article: Dinh Cao Huan Do, Petra Vasko, M. Ángeles Fuentes, Jamie Hicks, Simon Aldridge|2020|Dalton Trans.|49|8701|doi:10.1039/D0DT01447H
FPGA based digital lock-in amplifier for fNIRS systems
2018
Lock-In Amplifiers (LIA) represent a powerful technique helping to improve signals detectability when low signal to noise ratios are experienced. Continuous Wave functional Near Infrared Spectroscopy (CW-fNIRS) systems for e-health applications usually suffer of poor detection due to the presence of strong attenuations of the optical recovering path and therefore small signals are severely dipped in a high noise floor. In this work a digital LIA system, implemented on a Zynq® Field Programmable Gate Array (FPGA), has been designed and tested to verify the quality of the developed solution, when applied in fNIRS systems. Experimental results have shown the goodness of the proposed solutions.
Silicon Surface Passivation by ALD-Ga2O3: Thermal vs. Plasma-Enhanced Atomic Layer Deposition
2020
Silicon surface passivation by gallium oxide (Ga2O3) thin films deposited by thermal- and plasma-enhanced atomic layer deposition (ALD) over a broad temperature range from 75 °C to 350 °C is investigated. In addition, the role of oxidant (O3 or O-plasma) pulse lengths insufficient for saturated ALD-growth is studied. The material properties are analyzed including the quantification of the incorporated hydrogen. We find that oxidant dose pulses insufficient for saturation provide for both ALD methods generally better surface passivation. Furthermore, different Si surface pretreatments are compared (HF-last, chemically grown oxide, and thermal tunnel oxide). In contrast to previous reports, t…
Atomic Layer Deposition and Properties of Lanthanum Oxide and Lanthanum-Aluminum Oxide Films
2006
Atomic layer deposition (ALD) of lanthanum oxide on glass and silicon substrates was examined using lanthanum silylamide, La[N(SiMe 3 ) 2 ] 3 , and water as precursors in the substrate temperature range of 150-250 °C. The effect of pulse times and precursor evaporation temperature on the growth rate and refractive index was investigated. The films remained amorphous regardless of the deposition conditions. The resulting La 2 O 3 films contained noticeable amounts of hydrogen and silicon and were chemically unstable while stored in ambient air. Lanthanum aluminum oxide films were achieved with stoichiometry close to that of LaAlO 3 at 225°C from La[N(SiMe 3 ) 2 ] 3 , Al(CH 3 ) 3 , and H 2 O.…
SIC based solid state protections switches for space applications
2017
Development and technology maturation of Silicon Carbide (SiC) power transistors over the last 15 years has motivated its study in aerospace systems. When compared with Si devices, superior voltage blocking capacity and the capability of operation at higher temperatures, give important advantages in space power electronics applications, similar to what happens in terrestrial electronics. This paper discusses the use of SiC power transistors for Solid State Power Switches especially addressed to the space segment. Two applications will be covered, the first is the Solid State Shunt Switch, widely used in high power Direct Energy Transfer (DET) photovoltaic power regulators and the second is …
Parasitic Bipolar Action in SiC Power MOSFETs Demonstrated by Two-Photon Laser Experiment
2018
A two-photon absorption technique is explored for Silicon carbide power MOSFETs and power junction barrier Schottky diodes using a pulsed laser. The similarities in design between the specific MOSFETs and diodes tested permit using mechanisms existing in the different structures as explanation for observed current variation with laser position. The diode shows variation in average current with change in laser depth only, whereas the MOSFET shows variation both with shifts in depth and shifts in position across the striped geometry of the device. The variation is explained to be due to bipolar amplification of the charge carriers generated in the MOSFET when a pulse focus includes a channel …
Structural and morphological characterization of the Cd-rich region in Cd1-xZnxO thin films grown by atmospheric pressure metal organic chemical vapo…
2019
Abstract We have analysed the growth, morphological and structural characterization of Cd1-xZnxO thin films grown on r-sapphire substrates by atmospheric pressure metal organic chemical vapour deposition, mainly focusing on the Cd-rich rock-salt phase for its promising optical and technological applications. The evolution of the surface morphology and crystalline properties as a function of Zn content has been studied by means of high resolution x-ray diffraction and electron microscopy techniques. Monocrystalline (002) single-phase cubic films were obtained with Zn contents up to 10.4%, and with a low density of dislocations as a consequence of the optimized crystal growth process. Particu…
Optimization of physicochemical and optical properties of nanocrystalline TiO 2 deposited on porous silicon by metal-organic chemical vapor depositio…
2020
International audience; Titanium dioxide (TiO2) is very employed in solar cells due to its interesting physicochemical and optical properties allowing high device performances. Considering the extension of applications in nanotechnologies, nanocrystalline TiO2 is very promising for nanoscale components. In this work, nanocrystalline TiO2 thin films were successfully deposited on porous silicon (PSi) by metal organic chemical vapor deposition (MOCVD) technique at temperature of 550°C for different periods of times: 5, 10 and 15 min. The objective was to optimize the physicochemical and optical properties of the TiO2/PSi films dedicated for photovoltaic application. The structural, morphologi…
Validation of mathematical model for CZ process using small-scale laboratory crystal growth furnace
2018
The present material is focused on the modelling of small-scale laboratory NaCl-RbCl crystal growth furnace. First steps towards fully transient simulations are taken in the form of stationary simulations that deal with the optimization of material properties to match the model to experimental conditions. For this purpose, simulation software primarily used for the modelling of industrial-scale silicon crystal growth process was successfully applied. Finally, transient simulations of the crystal growth are presented, giving a sufficient agreement to experimental results.
Fluence effect on ion-implanted As diffusion in relaxed SiGe
2005
A systematic study on the fluence (5 × 108 − 4 × 1014 cm−2) dependence of ion-implanted As diffusion in relaxed Si1 − xGex alloys (with x = 0.2, 0.35 and 0.5) and silicon has been performed by the modified radiotracer and secondary ion mass spectrometry techniques. With fluences above 4 × 1011 cm−2 a clear fluence-dependent enhancement in arsenic diffusion was noted for Si1 − xGex. In case of arsenic-implanted silicon such fluence dependency was not observed. This can be assigned to enhanced implantation-induced damage formation and more deficient radiation damage recovery of SiGe.