Papers by Keyword: Silicon

Abstract: This paper demonstrates the transport of electron and hole carriers in two distinct hydrogenated amorphous semiconductor materials at different temperatures. Compared to crystalline materials, the amorphous semiconductors differ structurally, optically and electrically, hence the nature of carrier transport through such amorphous materials differ. Materials like hydrogenated amorphous silicon and amorphous IGZO have been used for the study of temperature dependent carrier transport in this paper. Simulation results have been presented to show the variation of free electron and hole concentration, trapped electron and hole concentration with energy at 300K for both the materials. The change in mobility with a change in the Fermi level has been plotted for different temperatures. The effect of temperature on Brownian motion mobility of electrons and holes in hydrogenated amorphous silicon and amorphous IGZO has been demonstrated towards the end of this paper.

Abstract: The channel material of a gate describes the operating condition of the MOSFET. A suitable operating condition prevails in MOSFETs if the transistors are quite enough to observe and control at the nanometer regime. An efficient gate and channel material have been proposed in this work which is based on the electrical properties they exhibit at the temperature of 300 K. The doping concentration for the electrons and holes is maintained to be 1Χ10¹⁹cm^-3 for the entire electronic simulator. The simulation results show that using La₂O₃ along with Indium Nitride (InN) material for the designing of Double-Gate (DG) MOSFETs provides better controllability over the transistor at a channel length of 50 nm. This proposed DG-MOSFET is more compliant than the conventional coplanar MOSFETs based on Silicon.

Abstract: Lithium iron phosphate (LiFePO₄) based material is one of the most prospective candidates as a cathode material in lithium-ion batteries because of its lower cost, safer, and environmental benignity compared to lithium cobalt oxide (LiCoO₂), which is commonly used for lithium-ion batteries manufacturing. However, its low conductivity is the obstacle of this material to solve, so that modification with the addition of silicon (Si) is expected to improve the electrochemical performance. Meanwhile, solid state reaction is considered simple and effective in LiFePO₄ crystal growth process. Therefore, Si-doped LiFePO₄ using solid state reaction in this research aims to study its structure and morphology as well as the effect of adding Si to its conductivity. The synthesis began with mixing LiH₂PO₄, Fe₂O₃, carbon black, and six-mole ratio variation of Si to LiFePO₄ using agate with ethanol: acetone addition then dried in an oven at 80°C and heated at 550°C in a furnace for 6 hours under argon atmosphere and sintering temperature of 870°C for 16 hours with the same condition. The sample of 3% mole ratio performed the highest conductivity of all variations with 3.01 x 10^-6 S.cm^-1, and was identified as Li_0.93Fe_1.07P_0.93O₄Si_0.7 with orthorhombic structure, Pnma space group (Ref. Code: ICSD 98-016-1792) with the highest peak at 2θ = 35.556° from XRD analysis with rectangular-like shape particle.

Abstract: The behavior of linear defects in n-and p-type silicon, generated by laser radiation is studied for pulse energy density 417 – 1083 mJ/cm2. The features of the nondestructive and destructive effects of the laser pulse on the surface defects formation of the semiconductor crystals are revealed. The formation and movement of dislocations in the crater region and the development of micro cracks, accompanied by acoustic waves are revealed.

Abstract: The paper is devoted to the urgent issue of processing the dust waste of metallurgical-grade silicon production, i.e. wet cleaning sludge, which contains a significant amount of valuable silica. The paper analyzes the formation of finely dispersed techno-genic materials that are generated in significant quantities (up to 120 t/d) at the Kremniy JSC. The composition and properties of the silicon production wet cleaning product have been studied. In analytical studies of the wet cleaning sludge samples, the modern certified analysis techniques have been used: laser diffraction, X-ray diffraction, and X-ray fluorescence. According to the analysis, the L:S ratio of liquid sludge is 2.1:1; after dehydration, the sludge cake has a grain size of 150 μm, with the prevailing (90 %) grain size of 59.65 μm in the test sample. The chemical composition of the sludge is 95.86 % SiO₂; therefore, the wet cleaning sludge is a valuable raw material to produce metallurgical-grade silicon. Based on the analysis of the composition and properties of the silicon production wet cleaning sludge sample, we have developed a program for its processing. Sustainable sludge processing techniques are aimed at obtaining a briquetted charge, which can be used as an additive to the main raw material.

Abstract: The behavior of linear defects in p-type silicon (111) carrying a direct current of density 0−15×10⁵ A/m² in the [110] direction are studied in the temperature range T=850–1000 K during isothermal annealing. The regularities of change in the linear density and maximum path of dislocations in slip lines are revealed. A model of linear defects displacement in silicon single crystals in the field of internal stresses under an electric current is proposed. Matching theory with experimental data has made it possible to reveal the dependence of this distribution on the internal stresses relaxation time.

Abstract: The effect of milling time on the microstructure evolution and formation of amorphous phase of Ti₆₀Si₄₀ alloy produced by mechanical alloying (MA) has been investigated. Laser diffraction, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Differential Scanning Calorimetry (DSC) were employed to characterize the particle size, morphology and structure of mechanically alloyed Ti₆₀Si₄₀. When the milling time is increased to 20 h, the particle size decreases from 23.7 to 4.7 μm, the shape of the particles changes to spherical and the crystalline structure is transformed into an amorphous phase. The amorphous Ti₆₀Si₄₀ alloy is stable when heating up to 750oC. Above this temperature, the cold crystallization of the intermetallic compounds Ti₅Si₃ and/or Ti₅Si₄ begins.

Abstract: This study presents a step towards exploring the possibility of using silicon materials as a surrogate to produce a multi-material 3D printed soft silicone brain model to be used in the investigation of Traumatic Brain Injury (TBI) in paediatric populations. Silicone represents a popular choice of material due to its viscoelastic properties, 3D printability, and capability to be tuned to possess different properties. Dynamic oscillatory shear tests were carried out for seven types of silicon materials at three different speeds against a different range of frequencies. The mechanical parameters response has been ranked on, which is the most appropriate to try. It also agrees with the range of reported paediatric brain tissue imitating grey and white matter as a surrogate brain material. Utilising of silicone for 3D printing represents a new approach to fabricate surrogate models that closely mimic biofidelic features and advance the medical engineering discipline.

Abstract: This paper describes a study on the remote plasma etching of silicon-based semiconductor wafers after laser separation. Several process parameters having impact on the chip reliability, expressed as changes in die material strength, have been studied and optimized. The results show the potential of fluorine-based plasma processing for cleaning dies and improving die performance and thus have a role as a process enabling advanced packaging technologies.

Abstract: Czochralski silicon single crystals were deformed in tensile tests along the direction at between 1173 K and 1373. Yield point phenomenon were observed in the specimens deformed at below 1273 K while continues yield was observed in the specimens deformed at above 1323 K. It is due to the effect of dislocation starvation in the used crystals. Work-hardening rates in stage II were consistent with those reported in fcc crystals such as copper. The onset of stage II was found to be active before the Schmid factor of the second slip system becomes larger than that of the primary slip system. Electron backscattered diffraction images indicated clear kink bands near grips and in the parallel portion. The kink bands were formed at the middle of stage I, which suggest that the formation of kink bands is a trigger of stage II.