Synthesis and Characterization of Mesoporous Silicon Oxynitride MCM-41 with High Nitrogen Content

Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N-2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).

Intense Yellow Photoluminescence from Silicon Oxynitride Films Prepared by Dual Ion Beam Sputtering

In this work, results on the study of the structure and photoluminescence (PL) properties of SiOxNy thin films are presented. The films were deposited at room temperature using a dual-ion-beam co-sputtering system. The XRD and TEM results show that the deposited films have an amorphous structure. In the XPS result, we find N 1s spectra consist of one symmetric single peak at 397.8 eV, indicating that the nitrogen atoms are mainly bonded to silicon. It is in agreement to the result of FTIR. In SiOxNy films, an intense single PL peak at 590 nm is observed. Furthermore, with the increase of the N content in the SiOxNy films, the intensity of the PL peak at 590 nm increases a lot. The PL peak of 590 nm is suggested to originate from N-related defects.

Interface effects on the electroluminescence spectra in amorphous-Si/silicon oxynitride multilayer structures

We report room-temperature electroluminescence (EL) from as-deposited amorphous-Si/silicon oxynitride multilayer structure prepared by plasma enhanced chemical vapor deposition. We prepared 8-period a-Si/SiOxNy multilayer with thickness of 4 nm both for the Si and SiOxNy sublayers. The EL spectral profile exhibits some obviously modulated features upon the barrier material. By adjusting the nitride/oxygen ratio in the barrier layer, the EL peak position can be tuned from 750 nm to 695 nm. From the result of the Raman and Fourier transform infrared results, the EL is attributed to the radiative recombination of electrons and holes in luminescent centers related to the interface. The different interface characteristics induce the shift of EL peak position.

Effect of oxygen concentration on resistive switching behavior in silicon oxynitride film

SiOxNy films with different oxygen concentrations were fabricated by reactive magnetron sputtering,and the resistive switching characteristics and conduction mechanism of Cu/SiOxNy/ITO devices were investigated.The Cu/SiOxNy/ITO device with SiOxNy deposited in 0.8-sccm O2 flow shows a reliable resistive switching behavior,including good endurance and retention properties.As the conductivity of SiOxNy increases with the increase of the oxygen content dynamical electron trapping and detrapping is suggested to be the conduction mechanism.The temperature dependent I-V measurement indicates that the carrier transport can be ascribed to the hopping conduction rather than the metallic conductive filament.

Etching characteristics of thin SiON films using a liquefied perfluorocarbon precursor of C_6F_(12)O with a low global warming potential

Perfluorocarbon gas is widely used in the semiconductor industry.However,perfluorocarbon has a negative effect on the global environment owing to its high global warming potential(GWP) value.An alternative solution is essential.Therefore,we evaluated the possibility of replacing conventional perfluorocarbon etching gases such as CHF_3 with C_6F_(12)O,which has a low GWP and is in a liquid state at room temperature.In this study,silicon oxynitride(SiON) films were plasma-etched using inductively coupled CF4+C_6F_(12)O+O_2 mixed plasmas.Subsequently,the etching characteristics of the film,such as etching rate,etching profile,selectivity over Si,and photoresist,were investigated.A double Langmuir probe was used and optical emission spectroscopy was performed for plasma diagnostics.In addition,a contact angle goniometer and x-ray photoelectron spectroscope were used to confirm the change in the surface properties of the etched SiON film surface.Consequently,the etching characteristics of the C_6F_(12)O mixed plasma exhibited a lower etching rate,higher SiON/Si selectivity,lower plasma damage,and more vertical etched profiles than the conventional CHF_3 mixed plasma.In addition,the C_6F_(12)O gas can be recovered in the liquid state,thereby decreasing global warming.These results confirmed that the C_6F_(12)O precursor can sufficiently replace the conventional etching gas.

High-temperature Reaction of Silica Fume-Si_3N_4 System

The specimens were prepared by molding the mixture of silica fume （ w（ SiO2 ） =94. 5% ; average particle size ： 0. 08 μm ） and silicon nitride （ ≤ 0. 074 mm ） with a mass ratio of 1 ： 1, carbon embedded firing at 1 300 ℃, 1 450℃, 1 500℃, 1 550 ℃ and 1 600 ℃ for 3 h in air, and then water-cooling, respectively. The microstructure and phase composition of the specimens were analyzed. The results show that： （1） silica fume reacts obviously with Si3N4 forming Si2N2O above 1 550 ℃. The edges and corners of Si3N4 grains become smooth and the Si3 N4 grains distribute in the continuous cementation phase of Si2N2O forming the dense structure of Si2N2o packed Si3N4 ; （2） below 1 500 ℃ , the edges and corners of Si3N4 grains are clear, Si2N2O doesn＇t form, and only SiO2 crystallizes from silica fume which happens obviously at 1 300 ℃.