- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
High-density cascade arc plasma sources for application to plasma windows for virtual vacuum interfaces
摘要： We develop two cascade arc plasma sources for application to plasma windows for virtual vacuum interfaces. For windowless vacuum–atmosphere separation, a compact arc discharge source having a channel diameter of 3 mm is fabricated, and an atmospheric Ar thermal plasma is generated. For an alternative differential pumping system, separating low- and high-pressure vacuum chambers, a larger arc device with an 8-mm diameter is also constructed, producing a high-density He plasma. The performances of the two cascade arcs as plasma windows are investigated. The 3-mm arc discharge generates a steep pressure gradient of Ar 100 kPa–100 Pa through the discharge channel, while the 8-mm discharge apparatus isolates the high-pressure side at 7 kPa from the lower pressure of 54 Pa. Emission spectroscopy of visible and vacuum UV radiation reveals the characteristics of the Ar and He plasmas. Spectral analysis yields a plasma temperature of around 1 eV in both discharges. Stark broadenings of the H-b and Ar I lines give an electron density of 6.5 (cid:2) 1016 cm(cid:3)3 for Ar 60 A with a gas ?ow rate of 1.0 l/min and 4.7 (cid:2) 1013 cm(cid:3)3 under a He 100-A and 0.45-l/min condition.
关键词： electron density,plasma temperature,emission spectroscopy,virtual vacuum interfaces,He plasma,cascade arc plasma sources,plasma windows,Ar thermal plasma
更新于2025-09-04 15:30:14
-
Influence of magnetic filter and magnetic cage in negative ion production in helicon oxygen plasma
摘要： Negative ion rich oxygen plasma at low pressure is produced in a Helicon Plasma Source setup, which is primarily designed to perform electronegative gas plasma experiments including the studies of ion-ion plasma. The negative ion fraction and hence the negative ion density are obtained by using a two probe technique in which the electron current is obtained by using an RF compensated cylindrical Langmuir probe and positive ion saturation current is obtained by using an RF compensated planar probe. By measuring the negative ion fraction, both with and without a magnetic filter, the importance of the magnetic filter field in the production of negative ions in oxygen plasma is investigated. The maximum value of negative ion fraction a (n?/ne) is calculated to be approximately around 9 when the value of temperature ratio c (Te/T?) is taken as 10. The observed negative ion fraction and other plasma parameters are explained by considering the set of reactions that are involved in the production and loss of negative ions.
关键词： magnetic cage,magnetic filter,helicon plasma,oxygen plasma,negative ion
更新于2025-09-04 15:30:14
-
Silicon Film Deposition Using a Gas-Jet Plasma-Chemical Method: Experiment and Gas-Dynamic Simulation
摘要： This paper presents the results of an experimental study, numerical calculation, and analysis within the framework of a gas-dynamic model of silicon ?lm deposition by a gas-jet plasma-chemical method. A numerical model of gas mixtures ?owing out of an annular nozzle unit and into a reactor is developed, and it allows one to determine a ?lm thickness distribution over the surface of substrates placed in the reactor and satisfactorily describes the experimental data obtained.
关键词： reactor,simulation,plasma-chemical deposition,thin silicon ?lms,free jet,electron-beam plasma,DSMC method
更新于2025-09-04 15:30:14
-
Research on the Gas Effect of Octafluorocyclobutane Plasma Jet at Atmospheric Pressure for Silicon Etching
摘要： The capacitively coupled radio frequency double-pipe plasma discharge jet is used for the etching process. An argon carrier gas is fed through the atmospheric-pressure plasma source; octafluorocyclobutane (C4F8) etch gas is injected into the plasma. Etchings were carried out on a crystalline silicon substrate. The etching characteristics are discussed and the etch rate tendency shows the reliance of C4F8 gas flow rate and oxygen addition. The optimum etching rate of 7.2 μm/min was obtained at a plasma power level of 100 W and C4F8 gas flow rate was 250 sccm. From surface profile detection, it displays the etch profile under this atmospheric-pressure plasma jet treatment. This plasma technique could offer a breakthrough for chamber-free dry etching processing.
关键词： plasma etching,Atmospheric-pressure plasma,octafluorocyclobutane,crystalline silicon
更新于2025-09-04 15:30:14
-
Near-infrared Zeeman spectroscopy for the spatially resolved measurement of helium emission spectra in Heliotron J
摘要： A passive spectroscopic method that can measure spatially resolved emission spectra only by observing from a single diagnostic port without assuming plasma symmetry was applied to the stellarator-heliotron device Heliotron J. The emission spectra from the inboard and outboard sides were separated using the difference in their Zeeman effects. On the basis of the fact that in a spectrum as a function of the wavelength, the magnitude of the wavelength splitting by the Zeeman effect relative to the Doppler broadening increases with the wavelength, the method was applied to a near-infrared helium emission line (He I 1s2s 3S?1s2p 3P, 1083 nm), and it was confirmed that the uncertainty in the separated spectra was reduced compared with that in the application to visible emission lines. From the emissivity of the separated spectra, the local recycling flux was evaluated using the inverse photon efficiency method.
关键词： Zeeman effect,plasma surface interaction,stellarator,recycling,plasma spectroscopy,tomography
更新于2025-09-04 15:30:14
-
Note: Plasma optical emission spectroscopy for water vapor quantification and detection during vacuum drying process
摘要： A methodology involving plasma optical emission spectroscopy driven by a direct current (dc) plasma source is developed to quantify water vapor concentration in a gaseous stream. The experimental setup consists of a dc driven low-pressure plasma cell in which the emission from the plasma discharge is measured by using an optical emission spectrometer. The emission from Hα at 656.2 nm—the first transition in the Balmer series, was found to be the most sensitive to the water vapor concentration in the gas stream. Consistent linear trends of the emission signals with respect to variation in concentration of water are observed for multiple combinations of operating parameters. This method has been applied to a vacuum drying process of a mock nuclear fuel assembly to quantify the concentration of water vapor during the drying process.
关键词： Hα emission,direct current plasma source,plasma optical emission spectroscopy,vacuum drying process,water vapor quantification
更新于2025-09-04 15:30:14
-
A micro-scale plasma spectrometer for space and plasma edge applications (invited)
摘要： A plasma spectrometer design based on advances in lithography and microchip stacking technologies is described. A series of curved plate energy analyzers, with an integrated collimator, is etched into a silicon wafer. Tests of spectrometer elements, the energy analyzer and collimator, were performed with a 5 keV electron beam. The measured collimator transmission and energy selectivity were in good agreement with design targets. A single wafer element could be used as a plasma processing or fusion first wall diagnostic.
关键词： electron beam,microchip stacking,silicon wafer,plasma processing,fusion first wall diagnostic,lithography,plasma spectrometer,collimator,energy analyzer
更新于2025-09-04 15:30:14
-
Innovative low temperature plasma approach for deposition of alumina films
摘要： Alumina films were deposited from a new plasma method using aluminum acetylacetonate (AAA) powder as precursor. The AAA was sputtered in argon and oxygen plasma mixtures. It was investigated the effect of the oxygen proportion (O2%) on the properties of the coatings. Deposition rate was derived from the layer height measured by profilometry. The elemental composition and molecular structure of the films were determined by Rutherford backscattering and infrared spectroscopies, respectively. Grazing incidence X-ray diffraction was used to investigate the microstructure of the films while hardness was determined by nanoindentation technique. Inspections on the surface morphology and on the film composition were conducted associating scanning electron microscopy and energy dispersive spectroscopy. Incorporation of oxygen affects the plasma kinetics and consequently the properties of the coatings. As moderated concentrations of oxygen (< 25%) are added, the structure is predominantly organic containing stoichiometric amorphous alumina. On the other hand, as high O2% (> 25%) are incorporated, the structure become rich in metallic aluminum with carbon rising at low proportions. The deposited layer is not homogeneous in thickness once the chemical composition of the precursor is changed by the action of the reactive oxygen plasma. Oxygen ablation on the film surface also contributes to the lack of homogeneity of the structure, especially as high oxygen proportions are imposed. Hardness data (0.5-2.0 GPa) corroborated the idea of an amorphous structure. Based on the results presented here it was possible to identify the oxygen concentration in the plasma atmosphere which mostly removed organics while preserving the stoichiometric alumina precipitation, subject of great relevance as one considers the reduction in the energy necessary for the creation of fully oxide coatings.
关键词： composition,reactive plasma sputtering,aluminum acetylacetonate,morphology,alumina,structure
更新于2025-09-04 15:30:14
-
Study of <i>In-Situ</i> Hydrogen Plasma Treatment on InGaZnO with Atmospheric Pressure-Plasma Enhanced Chemical Vapor Deposition
摘要： In the past few years, thin film transistors have a wide range of applications on display technology, material selection and quality for its active layer is critical for device performance. Traditional amorphous silicon (a-Si) silicon has a lot of advantages such as good productivity, short process and low-cost. It also has a lot of shortcomings on these applications on TFTs such as photosensitivity, light degradation, and opacity, etc. The dispute of the material based on a-Si:H as an active layer in TFT is low field effect mobility (~1 cm2/V · S) (M. Shur and M. Hack, J. Appl. Phys. 55, 3831 (1984)), photo sensitivity (low band gap about 1.7 V) and high deposition temperature (~400 °C) (M. Shur, et al., J. Appl. Phys. 66, 3371 (1989); K. Khakzar and E. H. Lueder, IEEE Trans. Electron Devices 39, 1438 (1992)). Amorphous In–Ga–Zn–O (IGZO) had attracted attention that compared with the conventional a-Si:H, due to its good properties of simultaneously high/low conductivity with high visual transparency via doping level. Oxide-based semiconductors, such as ZnO (G. Adamopoulos, et al., Appl. Phys. Lett. 95, 133507-3 (2009); H.-C. Cheng, et al., Appl. Phys. Lett. 90, 012113-3 (2007)) and IGZO (C. J. Chiu, et al., Electron Device Letters, IEEE 31, 1245 (2010); L. Linfeng and P. Junbiao, IEEE Transactions on Electron Devices 58, 1452 (2011)) have been reported for the active channel layer. These oxide-based materials offer good electrical properties and high transparency for thin film transistors, its high transmittance can be applied to fabricate the full transparent TFT on flexible substrate. With In-situ hydrogen plasma treatment on a-IGZO produced by atmospheric pressure-plasma enhanced chemical vapor deposition (AP-PECVD), the material characteristics of a-IGZO is studied.
关键词： AP-PECVD,a-IGZO,In-Situ Hydrogen Plasma
更新于2025-09-04 15:30:14
-
Investigation of Electrical Characteristics on AP-PECVD Fabricated Amorphous IGZO TFTs with Hydrogen Plasma Treatment
摘要： TFT panel production process can be divided into three kinds of technology. There have amorphous silicon (a-Si), low-temperature polysilicon (LTPS) and amorphous IGZO (a-IGZO) oxide. Traditional amorphous silicon (a-Si) silicon has a lot of advantages such as good productivity, short process and low-cost. It also has a lot of shortcomings on these applications on TFTs such as photosensitivity, light degradation, and opacity, etc. The dispute of the material based on a-Si:H as an active layer in TFT is low ?eld effect mobility (～1 cm2/V · S) (M. Shur and M. Hack, J. Appl. Phys. 55, 3831 (1984)), photo sensitivity (low band gap about 1.7 V) and high deposition temperature (～400 (cid:4)C) (M. Shur, et al., J. Appl. Phys. 66, 3371 (1989); K. khakzar and E. H. Lueder, IEEE Trans. Electron Devices IP: 146.185.205.202 On: Thu, 06 Dec 2018 10:11:54 39, 1438 (1992)). Amorphous In–Ga–Zn–O (IGZO) had attracted attention that compared with the conventional a-Si:H, in the past three years, a-IGZO thin ?lm transistors is more popular which compared with the other oxide semiconductors, because of its larger I on/I off ratio (>106(cid:2), smaller subthreshold swing (SS), better ?eld-effect mobility and better stability against electrical stress. Hydrogen plasma treatment is applied in improving a-IGZO TFTs active layer, which is fabricated by atmospheric pressure-plasma enhanced chemical vapor deposition (AP-PECVD), the electrical characteristics of a-IGZO TFTs is investigated.
关键词： a-IGZO TFTs,AP-PECVD,Hydrogen Plasma Treatment,Active Layer
更新于2025-09-04 15:30:14