RESUMEN
The objective of this study is to investigate the synthesis and influence of MoS2 on carbon nanowalls (CNWs) as supercapacitor electrodes. The synthesis of MoS2 on CNW was achieved by the introduction of hydrogen remote plasma from ammonium tetrathiomolybdate (ATTM) without deterioration of the CNWs. The topographical surface structures and electrochemical characteristics of the MoS2-CNW composite electrodes were explored using two ATTM-dispersed organic solvents-acetonitrile and dimethylformamide (DMF). In this study, CNW and MoS2 were synthesized using an electron cyclotron resonance plasma. However, hydrogen radicals, which transform ATTM into MoS2, were provided in the form of a remote plasma source. The electrochemical performances of MoS2-CNW hybrid electrodes with various morphologies-depending on the solvent and ATTM concentration-were evaluated using a three-electrode system. The results revealed that the morphology of the synthesized MoS2 was influenced by the organic solvent used and affected both the electrochemical performance and topographical characteristics. Notably, considerable enhancement of the specific capacitance was observed for the MoS2 with open top edges synthesized from DMF. These encouraging results may motivate additional research on hybrid supercapacitor electrodes and the rapid synthesis of MoS2 and other transition metal dichalcogenides.
RESUMEN
Optical emission spectroscopy is widely used in semiconductor and display manufacturing for plasma process monitoring. However, because of the contamination of the viewport, quantitative analysis is extremely difficult; therefore, qualitative analysis is used to detect species in the process. To extend plasma monitoring in advanced precise processes, the contamination problem of the viewport must be solved. We propose a new spectrum monitoring apparatus with a roll-to-roll transparent film window for optical diagnostics of a plasma system. By moving a transparent film in front of the viewport, contamination in the emission light path becomes negligible. However, the speed of the film should be optimized to reduce the maintenance period and to minimize measurement errors. We calculated the maximum thickness of SiO2, Si3N4, ITO, and the Ar/CHF3 plasma contaminant to suppress the electron temperature error measured by the line-intensity-ratio within 2% at 2 eV. The thickness of the Si3N4, ITO, and Ar/CHF3 plasma contaminant should be thinner than 12.5 nm, 7.5 nm, and 100 nm, respectively.
RESUMEN
The novel technique of Plasma-Assisted Vapor Deposition (PAVD) is developed as a new deposition method for thin metal films. The PAVD technique yields a high-quality thin film without any heating of the substrate because evaporated particles acquire energy from plasma that is confined to the inside of the evaporation source. Experiments of silver thin film deposition have been carried out in conditions of pressure lower than 10-3 Pa. Pure silver plasma generation is verified by the measurement of the Ag-I peak using optical emission spectroscopy. A four point probe and a UV-VIS spectrophotometer are used to measure the electrical and optical properties of the silver film that is deposited by PAVD. For an ultra-thin silver film with a thickness of 6.5 nm, we obtain the result of high-performance silver film properties, including a sheet resistance <20 Ω sq-1 and a visible-range transmittance >75%. The PAVD-film properties show a low sheet resistance of 30% and the same transmittance with conventional thermal evaporation film. In the PAVD source, highly energetic particles and UV from plasma do not reach the substrate because the plasma is completely shielded by the optimized nozzle of the crucible. This new PAVD technique could be a realistic solution to improve the qualities of transparent electrodes for organic light emission device fabrication without causing damage to the organic layers.
