Papers by Keyword: Silicon Oxynitride

Abstract: In silicon wafer manufacturing for solar cells, the hazardous sawing waste results in serious environmental problems. In this paper, a novel approach for the recycling and reusing of slurry waste is reported. The results show that slurry waste is recycled and reused completely, and composite material of Si₃N₄-Si₂N₂O-SiC is prepared. The residual gas from oxygen enrich gas production is used, which reduced cost effectively. In addition, the reaction is exothermic, which is also energy saving and ensure the production to be continuous without external heat source. The mechanism was also discussed in this paper.

Abstract: The distribution status of trace oxygen in the ferro-silicon nitride (Fe₃Si-Si₃N₄) was investigated at the present, which was prepared by flash combustion synthesis method from FeSi75. The results showed that while the grain size of FeSi75 used in preparing Fe₃Si-Si₃N₄ was less than0.074 mm, “active oxidation” occurred firstly, silicon was oxidized to form gaseous SiO(g), oxygen partial pressure was reduced in the system, silicon reacted with nitrogen directly to form Si₃N₄ while the system oxygen partial pressure approached less than 10^-19MPa (T=1823K). O₂(g) promoted the formation of Si₃N₄, Gaseous SiO(g) finally reacted with nitrogen and Si to form Si₂N₂O. The ferro silicon nitride was characterized by X-ray diffractometer and scanning electron microscope, the distribution of Si₂N₂O was uneven in the silicon nitride, and Si₂N₂O mainly distributed around Fe₃Si or near the hole.

Abstract: In this work, a SiON film with 25.78% nitrogen contents in film composition was deposited by RF magnetron sputtering. Micro SiON cantilevers were fabricated using MEMS sacrificial layer technology for tests. The micro-cantilever bending tests were done with the help of nanomechanical test system to characterize the Young’s modulus of the SiON. The results showed that the Young’s modulus of the SiON was 256 GPa. Because cantilevers can release the residual stress of the SiON film, the Young’s modulus we gained was more accurate than that early gained by other measuring methods.

Abstract: Extra-long molecular-dynamics simulations are performed to study the interplay between dielectric properties and microstructures of silicon oxynitride. We quantitatively obtained the ionic permittivity and its linear dependence on nitrogen concentration. Analyses on microstructure of the oxynitride show that, as the N concentration increases, N atoms enter Si-O networks creating smaller-sized rings. While overall tendency of dielectric constant is monotonic increase on the N concentration, microscopic characteristics, such as local displacement of atoms, are strongly depend on local bonding environments.

Abstract: The epitaxial silicon oxynitride (SiON) layer grown on a 6H-SiC(0001) surface is studied with core level photoemission spectroscopy. Si 2p spectra show three spectral components other than the bulk one. Chemical shifts and emission angle dependence of these components are well explained within a framework of a determined structure model of the SiON layer.

Abstract: Silicon oxynitride films were deposited in very-high-frequency (40.68 MHz) plasma enhanced chemical vapor deposition (VHF-PECVD), and subsequently annealed between 400 and 1200°C in N2 ambient. The effect of annealing temperature on the PL characteristics of the samples was investigated. The experimental results reveal that a broad PL peak around 430 nm (2.88eV) appears in all of the samples. The maximum intensity of this broad PL peak was obtained in the sample annealed at 400°C. The PL characteristics of the annealed samples were discussed.

Abstract: Si3N4-Si2N2O-TiN composite ceramics were in-situ fabricated by using following reactions of (1) 3TiO2 + Si3N4 → 3TiN + 3SiO2 + N2 and (2) Si3N4+ SiO2 → 2Si2N2O. The mixed powder of α-Si3N4, Al2O3, Y2O3 and TiO2 was hot-pressed at 24 MPa and 1800°-1900°C for 1-4 h in N2. Sintered composite ceramics were characterized by XRD, SEM, TEM, four-point bending test and Vickers indentation method. XRD results and TEM observation showed that TiN and amorphous SiO2 were formed at 1250°C by the reaction (1), and the Si2N2O phase formed by reaction (2) above 1800°C. Si3N4-Si2N2O-TiN composites consisted of ≥2 m sized Si2N2O grains with TiN and Si3N4 grains. Hardness and fracture strength of the composites were comparable to those of Si2N2O ceramics, with fracture toughness being improved at 5vol% TiN containing composites.

Abstract: Oxidation behavior of R4Si2O7N2 (J-phase; R = Y and rare-earth element) has been investigated by thermometric measurements in air. All R4Si2O7N2, of which the powder samples are prepared by gas-pressured sintering method under 1 MPa of N2 gas, are oxidized to R2SiO5 with an exothermic reaction in air under an ambient pressure. The oxidation temperature to produce the final oxide increases from c.a. 930 to 1060 °C with decreasing the ionic radii of the rare earth elements.

Abstract: Y-TZP presents excellent properties at room temperature but these properties decrease as the temperature increases. This paper studies the behavior 20vol%Si3N4-SiC when added in YTZP matrix and heated under no pressure system. Al2O3 and Y2O3 were used to maintain the stability of the matrix and as sintering aids. The addition of Si3N4 and SiC in a Y-TZP matrix leads to formation of silicon oxynitride and it increases the mechanical properties like toughness and hardness. The mixture was milled and molded by CIP. Samples were heated at 1500°C, 1600°C and 1700°C for 2h without pressure under atmospheric conditions in bed-powders of Si3N4. Samples were characterized by XRD. Density, hardness, toughness, bending strength were measured. The structure of the material was observed in SEM/EPMA to verify the distribution of the materials in the composite. The formation of Si2N2O was observed in the sintered material and it showed an increment of both hardness and toughness as temperature increases. The samples presented considerable resistance of oxidation at 1000°C.

Abstract: In this work we present results of Si/SiO2/SiON/SiO2 waveguides fabricated by means of ECR-PECVD. In order to change refraction index and simultaneously to reduce losses related with hydrogen, we have used N2 as precursor gas for controlling the nitrogen to oxygen relation present in the samples. The composition of the samples were carefully controlled by RBS and ERDA analysis. The refractive index and thickness were measured by using a prisma coupler method at a wavelength of 632.8 nm.