- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Dielectric properties of porous SiC/Si3N4 ceramics by polysilazane immersion-pyrolysis
摘要： The SiC nanotubes were synthesized on porous Si3N4 matrix by polysilazane immersion-pyrolysis. The β-SiC and free C contents increased with the increasing dipping times, which cause some clear vibration and loss peaks of the dielectric constant patterns emerged at around 12.9 GHz and 14.7 GHz in the samples of 20 wt% and 30 wt% benzoic acid, respectively. The re?ectivity of the obtained ceramics were ?7dB ～ ?10dB from the frequency of 8 GHz–18 GHz, which means that the amount of 80%–90% electromagnetic wave could be attenuated. The ceramics containing 40 wt% benzoic acid showed the high loss, low re?ectivity and a wide absorbing band, indicating the high absorbing e?ciency and good dielectric properties.
关键词： Dielectric properties,Si3N4,Dipping,SiC
更新于2025-11-21 11:18:25
-
Influence of GaN- and Si?N?-Passivation Layers on the Performance of AlGaN/GaN Diodes With a Gated Edge Termination
摘要： This paper analyses the influence of the GaN and Si3N4 passivation (or 'cap') layer on the top of the AlGaN barrier layer on the performance and reliability of Schottky barrier diodes with a gated edge termination (GET-SBDs). Both GaN cap and Si3N4 cap devices show similar dc characteristics but a higher density of traps at the SiO2/GaN interface or/and an increase of the total dielectric constant in the access region result in higher RON-dispersion in GaN cap devices. The leakage current at medium/low temperatures in both types of devices shows two low-voltage-independent activation energies, suggesting thermionic and field-emission processes to be responsible for the conduction. Furthermore, a voltage-dependent activation energy in the high-temperature range occurs from low voltages in the GaN cap devices and limits their breakdown voltage (VBD). Time-dependent dielectric breakdown measurements show a tighter distribution in Si3N4 cap devices (Weibull slope β = 3.3) compared to GaN cap devices (β = 1.8). Additional measurements in plasma-enhanced atomic layer deposition (PEALD)-Si3N4 capacitors with different cap layers and TCAD simulations show an electric field distribution with a strong peak within the PEALD-Si3N4 dielectric at the GET corner, which could accelerate the formation of a percolation path and provoke the device breakdown in GaN cap SBDs even at low-stress voltages.
关键词： Si3N4 cap,GaN cap,AlGaN/GaN Schottky diode,reliability,breakdown voltage,passivation layer,off-state,Activation energy
更新于2025-09-23 15:23:52
-
823 mA/mm drain current density and 945 MW/cm2 Baliga’s figure of merit enhancement-mode GaN MISFETs with a novel PEALD-AlN/LPCVD-Si3N4 dual gate dielectric
摘要： In this letter, we demonstrate a novel PEALD-AlN/LPCVD-Si3N4 dual gate dielectric employed in enhancement-mode GaN MISFETs, where the gate recess is fabricated based on our proposed self-terminating gate recess etching technique using GaN cap layer as recess mask. By using LPCVD-Si3N4 and PEALD-AlN dual gate dielectric layer, the devices exhibit a high quality gate dielectric and a good GaN channel interface, yielding a high gate swing up to 18V and a high channel effective mobility of 137 cm2/V?s at such high gate bias. Thus, the fabricated devices feature a high maximum drain current density of 823 mA/mm, a threshold voltage of 2.6 V, an on-resistance of 7.4 Ω?mm, and an ON/OFF current ratio of 108 with gate-drain distance of 2 μm. Meanwhile, a high OFF-state breakdown voltage of 1290 V is achieved with 10 μm gate-drain distance. The corresponding specific on-resistance is as low as 1.76 mΩ?cm2, leading to a high Baliga’s ?gure of merit of 945 MW/cm2.
关键词： self-terminating etching,enhancement-mode GaN MISFETs,plasma-enhanced atomic layer deposition (PEALD) AlN,LPCVD Si3N4
更新于2025-09-23 15:21:21
-
Recycling of silicon scraps by directional solidification coupled with alternating electromagnetic field and its electrical property
摘要： In this paper, alternating electromagnetic field and directional solidification are used to separate SiC and Si3N4 in polycrystalline silicon tailings. It is found the inclusion particles move downward at the center of the ingot and moving upward at the edge of the ingot by a variety of forces during the directional solidification process. The electromagnetic force accelerates the melt flow and enhances the lift force, so that larger particles can be pushed to the top of the ingot. Rod-shaped Si3N4 and block-shaped SiC particles show symbiotic relationship between each other. The aggregation of inclusion particles adsorbs metallic impurities, especially volatile metals, due to the effects of mushy region and short-circuit diffusion. The average conversion efficiency of the solar cells (Al-BSF method) prepared using the recycled silicon reached 18.56%, which meets the demand of the solar cells.
关键词： SiC,Alternating magnetic field,Directional solidification,Si3N4,Polycrystalline silicon
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Si3N4 Waveguide-Coupled Microdisk Resonators with a Quality Factor of 107
摘要： We design and fabricate dispersion-engineered ~830nm-thick Si3N4 waveguide-coupled microdisks. Our resonators show a loaded quality (Q)-factor of ~1×107. We observe optical parametric oscillations in a 345μm-radius microdisk with a threshold pump power of ~50 mW in the waveguide.
关键词： Stoichiometric Si3N4 micordisks,optical parametric oscillations,whispering-gallery modes,high-Q resonators
更新于2025-09-16 10:30:52
-
Inverse analysis of the residual stress in laser-assisted milling
摘要： In laser-assisted milling, higher temperature in shear zone softens the material potentially resulting in a shift of mean residual stress, which significantly affects the damage tolerance and fatigue performance of product. In order to guide the selection of laser and cutting parameters based on the preferred mean residual stress, inverse analysis is conducted by predicting residual stress based on guessed process parameters, which is defined as the forward problem, and applying iterative gradient search to find process parameters for next iteration, which is defined as the inverse problem. An analytical inverse analysis is therefore proposed for the mean residual stress in laser-assisted milling. The forward problem is solved by analytical prediction of mean residual stress after laser-assisted milling. The residual stress profile is predicted through the calculation of thermal stress, by treating laser beam as heat source, and plastic stress by first assuming pure elastic stress in loading process, then obtaining true stress with kinematic hardening followed by the stress relaxation. The variance-based recursive method is applied to solve inverse problem by updating process parameters to match the measured mean residual stress. Three cutting parameters including depth of cut, feed per tooth, and cutting speed, and two laser parameters including laser-tool distance and laser power, are updated with respected to the minimization of resulting residual stress and measurement in each iteration. Experimental measurements are referred on the laser-assisted milling of Ti–6Al–4 V and Si3N4. The percentage difference between experiments and predictions is less than 5% for both materials, and the selection is completed within 50 loops.
关键词： Residual stress,Ti–6Al–4V,Si3N4,Laser-assisted milling,Inverse analysis,Iterative gradient search
更新于2025-09-16 10:30:52
-
Hybrid Integrated Semiconductor Lasers with Silicon Nitride Feedback Circuits
摘要： Hybrid integrated semiconductor laser sources offering extremely narrow spectral linewidth, as well as compatibility for embedding into integrated photonic circuits, are of high importance for a wide range of applications. We present an overview on our recently developed hybrid-integrated diode lasers with feedback from low-loss silicon nitride (Si3N4 in SiO2) circuits, to provide sub-100-Hz-level intrinsic linewidths, up to 120 nm spectral coverage around a 1.55 μm wavelength, and an output power above 100 mW. We show dual-wavelength operation, dual-gain operation, laser frequency comb generation, and present work towards realizing a visible-light hybrid integrated diode laser.
关键词： low-loss Si3N4 waveguides,dual-wavelength laser,laser frequency comb,InP semiconductor optical amplifier,integrated photonic circuits,semiconductor laser,hybrid integration,narrow intrinsic linewidth
更新于2025-09-16 10:30:52
-
Analysis of Si3N4 waveguides for on-chip gas sensing by optical absorption within the mid-infrared region between 2.7 and 3.4???μm
摘要： We theoretically investigated the use of a Si3N4 on SiO2 waveguide as an optical interaction part with sensed molecules for multi-gas wideband on-chip spectroscopic sensing. From the analysis, we show that a simple strip Si3N4 waveguide can be employed to achieve acceptable values of performance in term of detection limit, compactness, polarization, and fabrication tolerance for the detection of water vapor (H2O), carbon dioxide (CO2), Nitrous oxide (N2O), Ammonia (NH3), Ethylene (C2H4), and Methane (CH4) gas molecules, with a wideband operation between 2.7 and 3.4 μm optical wavelength. The results show that a simple Si3N4 waveguide structure could attain competitive performance required for generic on-chip spectroscopic sensing for environmental and agricultural usage.
关键词： gas sensing,optical absorption,mid-infrared,on-chip spectroscopic sensing,Si3N4 waveguide
更新于2025-09-16 10:30:52
-
Laser-induced Si3N4–TiN ceramics degradation
摘要： This paper presents the process of degradation of the surface layer of Si3N4?TiN ceramics induced by a pulsed Nd:YAG laser. The dissociation of silicon nitride and titanium nitride in the irradiation zone is turned out to yield in a silicon depletion and so the zone becomes enriched with titanium, which, in turn, leads to the formation of TiSi2. This process of the TiSi2 formation can be considered as a ceramics metallization and its concentration depends on the energy delivered by the laser. The expansion of dissociation/evaporation products through the atmosphere is accompanied by the formation of SiO2 and TiO2, which are then deposited on the substrate as an amorphous ?lm of complex composition.
关键词： Surface phase transformation,(Si3N4 ? TiN):(Al2O3+Y2O3) ceramics,Film formation
更新于2025-09-12 10:27:22
-
Athermalization of a self-assembled rolled-up TiO2 microtube ring resonator through incorporation of a positive thermo-optic coefficient material in planar bilayers
摘要： For the first time, this paper theoretically and experimentally investigates the thermal stability of optical filters based on self-assembled TiO2 rolled-up microtube ring resonators (RUMRs) by incorporating positive thermo-optic coefficient (TOC) materials (e.g., SiO2 and/or Si3N4). The influence of the TOC, refractive index, and thickness of the positive TOC materials on the filtering performance of the TiO2 RUMR is theoretically studied. The results illustrate that an increase in temperature leads to a blueshift in the resonant wavelength of the RUMR-based optical filter, which changes at a rate of ? 33.3 pm/K owing to the negative TOC of TiO2 (? 4.9 ± 0.5 × 10?5/K). By increasing the thickness of SiO2 or Si3N4 as a positive TOC material together with TiO2, the temperature-induced resonant shifts of TiO2/SiO2 and/or TiO2/Si3N4 RUMRs are theoretically obtained. The TIRS varies between ? 40 pm/K (? 22 pm/K) and about 30 pm/K (22 pm/K) for TiO2/SiO2 (TiO2/Si3N4) RUMRs. It is shown that thermal stability occurs when the thickness of the SiO2 (Si3N4) layer is ~ 16 nm (12 nm). At the end of this study, as a proof of concept, an experiment is demonstrated by fabricating an RUMR based on TiO2/SiO2 on the flat silicon wafer. The experimental results show that the athermalization of the system is experimentally achieved by selecting the appricated thickness ratio of TiO2/SiO2. This novel approach for athermalization of the resonators opens up interesting perspectives on the implementation of vertical and multi-routing coupling between photonic and optoelectronic layers and more specifically in a three-integration fashion.
关键词： TiO2,Rolled-up microtube ring resonators,SiO2,Athermalization,Si3N4,Thermo-optic coefficient
更新于2025-09-12 10:27:22