Papers by Keyword: Oxynitride

Abstract: We have fabricated a new semiconducting material, (ZnO)_x(InN)_1-x (called ZION hereafter), which is a pseudo-binary alloy of wurtzite ZnO (band gap: 3.4 eV) and wurtzite InN (band gap: 0.7 eV). We have succeeded in fabricating epitaxial (ZnO)_0.82(InN)_0.18 films on ZnO templates by RF magnetron sputtering. XRD measurements show that the full width at half maximum of the rocking curves from (101) plane and (002) plane are significantly small of 0.11 ̊ and 0.16 ̊, respectively, indicating good in-plane and out-of-plane crystal alignment. High crystal quality of the films was also proved by deducing the defect density from XRD analysis showing that the edge type dislocation density is low of 8.2×10⁸ cm^-2. Furthermore, we observed room temperature photoluminescence from ZION films as a parameter of incident angle of He-Cd laser light. The results indicate that an emission peak of 2.79 eV is originated from ZION.

Abstract: The fabrication of thin-film transistor devices incorporating active semiconductors based on zinc oxynitride (ZnON) compound is presented. It is demonstrated that the addition of appropriate dopant, gallium, in ZnON, suppresses the formation of shallow donor, nitrogen vacancies, and significantly improves electrical characteristics of the resulting TFT. The Ga:ZnON devices with field-effect mobility values exceeding 50 cm²/Vs are achieved, which makes them suitable as switching or driving elements in next-generation flat-panel displays.

Abstract: The crystal structure and luminescent properties of synthesized SrSi2O2N2: Yb2+ phosphors have been investigated to seek for convention phosphor for white light-emitting diode applications. The Sr1-xYbxSi2O2N2 phosphors have yellow-red luminescence under the exciting of blue light, which is attributed to the 4fn↔4fn-15d transitions of Yb2+. Although the chemical compositions for Sr1-xYbxSi2O2N2 materials are different, no shifts are observed from the excitation and emission spectra.

Abstract: We demonstrated the impact of plasma nitridation on thermally grown GeO2 for the purposes of obtaining high-quality germanium oxynitride (GeON) gate dielectrics. Physical characterizations revealed the formation of a nitrogen-rich surface layer on the ultrathin oxide, while keeping an abrupt GeO2/Ge interface without a transition layer. The thermal stability of the GeON layer was significantly improved over that of the pure oxide. We also found that although the GeO2 layer is vulnerable to air exposure, a nitrogen-rich layer suppresses electrical degradation and provides excellent insulating properties. Consequently, we were able to obtain Ge-MOS capacitors with GeON dielectrics of an equivalent oxide thickness (EOT) as small as 1.7 nm. Minimum interface state density (Dit) values of GeON/Ge structures, i.e., as low as 3 x 1011 cm-2eV-1, were successfully obtained for both the lower and upper halves of the bandgap.

Abstract: Local structures of indium oxynitride (InON) nano-crystal prepared by reactive gas-timing RF magnetron sputtering technique are under investigation. Since the optical properties of these InON thin films depend on gas-timing ratio, the local structure analysis is needed in order to determine the relation between the gas timing ratio and its optical properties. In this work, InON thinfilm with 30:0 seconds (N2:O2) gas-timings ratio was analyzed for its local structure using X-ray absorption fine structure (XAFS) technique in conjunction with first principle calculation. The results indicate that the crystal structure of the film is wurtzite structure which is a typical structure of InN. However from the results of Auger Electron Spectroscopy (AES), there are oxygen contents in the film. Since XAFS analysis confirmed the 4-fold local structure of Indium atom, these oxygen atoms must be substituted in nitrogen sites with slightly changing the local structure of Indium atom. The best fit of XAFS data indicated that there is an oxygen atom substituted in nitrogen site of the 4-fold indium.

Abstract: This paper provides an overview of the preparation of M-Si-Al-O-N glasses and outlines the effects of composition on properties. As nitrogen substitutes for oxygen in sialon glasses, increases are observed in glass transition and softening temperatures, viscosities, elastic moduli and microhardness. If changes are made to the cation ratios or different rare earth elements are substituted, properties can be modified. The effects of these changes on mechanical properties of silicon nitride based ceramics and sialons are discussed. New research on M-Si-Al-O-N-F glasses is outlined.

Abstract: Multiternary nitride and oxynitride compounds doped with rare earth ions, such as Eu2+ and Ce3+ have been enthusiastically applied as various phosphors to white LED. New red and green phosphors, CaAlSiN3:Eu and Ba3Si6O12N2:Eu, have been successfully synthesized, recently. The red phosphor has intense emission around 650 nm under two different irradiations at 405 and 455 nm from blue- and near UV-LED chips, respectively; while strong emission is observed around 520 nm from the green phosphor. Both phosphors also show small thermal quenching over the temperatures up to 150 °C. In addition, both LaSi3N5:Ce and La3Si8O4N11:Ce in lanthanum silicon nitride and oxynitride were examined as candidates for a blue phosphor in white LED with near UV-LED chip.

Abstract: Secondary Ion Mass Spectrometry (SIMS) is frequently used in the characterization of thin films, coatings, diffusion processes, materials composition and in the analysis of implants. The SIMS technique has been continuously developed for more than 30 years. One of the main drivers was semiconductor technology. Standard implants in Si like B, As and P, implanted with a few keV to MeV energy are routinely measured with high precision. But nowadays with implant energies of 500 eV and below, when ultra shallow structures are examined, the desired information is in the first few nm to some tens of nm. This has a great impact on the analytical requirements and quantification procedures. Some of these aspects will be examined in this contribution.

Abstract: TiB2 coatings were plasma sprayed in air and were studied by XPS. There are five elements in the top surface of the studied coatings, namely, B, C, N, O and Ti. Oxygen pick-up in the coatings results in formation of oxides of boron and titanium. Nitrogen was shown to exist in N-Ti and O-N-Ti in the coating. Depending on the spraying parameters, mono-boride as well as di-boride was also detected in the studied coatings. With careful peak fitting it was shown that oxygen may exist in the coating as dissolved atomic O in addition to as lattice oxygen in the oxide of boron and titanium.

Abstract: Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.