- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
AlGaN/GaN MIS-HEMT with PECVD SiNx, SiON, SiO2 as Gate Dielectric and Passivation Layer
摘要： Three different insulator layers SiNx, SiON, and SiO2 were used as a gate dielectric and passivation layer in AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMT). The SiNx, SiON, and SiO2 were deposited by a plasma-enhanced chemical vapor deposition (PECVD) system. Great differences in the gate leakage current, breakdown voltage, interface traps, and current collapse were observed. The SiON MIS-HEMT exhibited the highest breakdown voltage and Ion/Ioff ratio. The SiNx MIS-HEMT performed well in current collapse but exhibited the highest gate leakage current density. The SiO2 MIS-HEMT possessed the lowest gate leakage current density but suffered from the early breakdown of the metal–insulator–semiconductor (MIS) diode. As for interface traps, the SiNx MIS-HEMT has the largest shallow trap density and the lowest deep trap density. The SiO2 MIS-HEMT has the largest deep trap density. The factors causing current collapse were confirmed by Photoluminescence (PL) spectra. Based on the direct current (DC) characteristics, SiNx and SiON both have advantages and disadvantages.
关键词： interface traps,MISHEMT,gallium nitride,PECVD,current collapse,dielectric layer
更新于2025-09-23 15:22:29
-
Dispersion characteristics of terahertz transverse electric mode in a smooth-wall cylindrical waveguide with a degenerate plasma layer
摘要： The propagation of transverse electric mode in a cylindrical metallic smooth-wall waveguide contains a dielectric rod and a cold collisionless unmagnetized degenerate plasma layer is analytically investigated in the terahertz frequency region. The dispersion relations of fast and slow waves for this mode are derived and solved numerically. The effects of geometrical and physical parameters such as dielectric, plasma and metal radii, and dielectric permittivity on the dispersion characteristics of terahertz transverse electric mode and its frequency spectrum are studied. It is shown that the decrease of dielectric permittivity and metal radius, and the increase of degenerate plasma radius leads to higher frequency fast waves. It is also indicated that an increase in the dielectric radius results in a decrease in the frequency of fast waves. In addition, it is found that by reducing the dielectric rod radius and with increasing metal radius, the frequency is increased in the slow waves. Finally, it is shown that the increase in dielectric permittivity causes a decrease in the frequency of both fast and slow waves.
关键词： Dielectric layer,Waveguide,Group velocity,Unmagnetized degenerate plasma,Dispersion relation
更新于2025-09-23 15:21:01
-
[IEEE 2018 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Cartagena des Indias (2018.9.10-2018.9.14)] 2018 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Two-parameter expansions and ray representation of the fields diffracted at thin-to-thick curved dielectric layers and conducting bodies
摘要： In this study, we introduce a uni?ed approach that allows to construct the asymptotic procedure for various high-frequency electromagnetic diffraction problems at curved dielectric, conducting, and absorbing layers, and to obtain the curvature correction to solutions. The method proposed is based on the combination of ray representations and the expansions typical for the boundary-layer technique: we seek the ?eld as a ray series, whose coef?cients are the functions of a point in space, the more “stretched” along the normal to one of the boundaries, the thicker layer is. The asymptotics are derived both in 2D and 3D formulations and are validated by comparison with analytical and numerical solutions of canonical problems.
关键词： dielectric layer,curvature,conductors,higher-order diffraction
更新于2025-09-19 17:15:36
-
Facile approach for the periodic poling of MgO-doped lithium niobate with liquid electrodes
摘要： The emerging quantum communication applications advance the rapid development of up-conversion single-photon detectors and entangled photon-pair sources, of which the core components are both based on frequency conversion in periodically poled lithium niobate (PPLN) waveguides. The MgO-doped congruent lithium niobate (Mg:LN) is known as the most promising material for the fabrication of PPLN because of its attractive properties, but the leakage current complicates the high-quality periodic poling of Mg:LN, especially for the technique with liquid electrodes. In this paper, we demonstrated an effective approach to suppress the leakage current by using SiO2 dielectric layer of appropriate thickness, and high-quality periodic poling has been realized in 5 mol.% Mg:LN wafers with the diameter of 76.2 mm based on the electric-field poling method using liquid electrodes. The ease of clear remove of the liquid electrodes benefits for the fabrication of waveguides on the wafer surface, and the wafer-level manufacture of PPMgLN with easy operation and high rate of finished products facilitates the mass production of PPMgLN devices for quantum communication applications.
关键词： liquid electrodes,leakage current,Mg:LN,periodic poling,SiO2 dielectric layer
更新于2025-09-19 17:15:36
-
[IEEE 2017 IEEE 44th Photovoltaic Specialists Conference (PVSC) - Washington, DC (2017.6.25-2017.6.30)] 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC) - High resolution THz scanning for optimization of dielectric layer opening process on doped Si surfaces
摘要： Diffused IBC solar cells based on non-fire-through (NFT) metallization can achieve higher performance with respect to FT metallization, thanks to lower contact resistance. Less resistive contacts allows for lower metal fraction and thus lower contact recombination. For the application of NFT contacts, the rear side dielectric passivation layer needs to be locally opened. Standard processes for dielectric opening include laser ablation, use of etching pastes or masking and etching. In all this cases it is important that the opening process does not cause any damage to the diffusion below the contacts. We present a fast inspection method based on THz near-field scanning that allows investigating the diffusion layers after dielectric opening with spatial resolution suited for the small feature size of standard IBC solar cells. This method can be used to optimize crucial parameters of the dielectric opening without processing full cells. In this paper, we use THz scanning to optimize the curing temperature of the etch paste used to open the dielectric passivation layers on solar cells half-fabricates. After optimization, full cells are processed with top efficiency of 20.8%.
关键词： THz scanning,NFT metallization,dielectric layer opening,solar cells,doped Si surfaces
更新于2025-09-11 14:15:04
-
[IEEE 2018 Days on Diffraction (DD) - St.Petersburg, Russia (2018.6.4-2018.6.8)] 2018 Days on Diffraction (DD) - Propagation of electromagnetic waves in a shielded dielectric layer with cubic nonlinearity
摘要： An eigenvalue problem describing propagation of transverse magnetic waves in a shielded dielectric layer with cubic nonlinearity is studied. It is proved that even for small value of the nonlinearity coefficient, the nonlinear problem has infinitely many nonperturbative solutions (eigenvalues and eigenfunctions), whereas the corresponding linear problem always has a finite number of solutions.
关键词： eigenvalue problem,shielded dielectric layer,nonperturbative solutions,cubic nonlinearity,transverse magnetic waves
更新于2025-09-09 09:28:46
-
Fabrication of FP-cavity-based monolithic full-color filter arrays using a template-confined micro-reflow process
摘要： Fabry-Perot (FP) resonators are of great interest for various applications due to their high stability, environmental friendliness and chemical inertia. However, it is still technically challenging to obtain compact monolithic MDM-based color filter array (CFA) because of the difficulty in achieving microscale-pixelated stepwise dielectric films with designed thickness. In this work, we proposed a template-confined thermal reflow approach to fabricate monolithic CFA based on silver-polymethyl methacrylate-silver (Ag-PMMA-Ag) sandwich configuration. Via template-confined thermal reflow of periodic PMMA nanogratings with different filling density, the thickness of PMMA dielectric layer in each pixel can be independently controlled, enabling the spectral tunability across the whole visible light region with high transmission efficiency and narrow linewidth. Compared to conventional multiple deposition technique, the approach we proposed is able to control the thickness of dielectric film via a single exposure step and can be potentially applied in high-throughput production by combining nanoimprint lithography.
关键词： micro-reflow,monolithic stepwise dielectric layer,PMMA,color filter array,Fabry-Perot resonator
更新于2025-09-04 15:30:14