The development of a large-area plasma source with high density plasmas is desired for a variety of plasma processes from microelectronics fabrication to flat panel display device fabrication. In this study, a novel internal-type linear inductive antenna referred to as “double comb-type antenna” was used for a large-area plasma source with the substrate area of 880 mm × 660 mm and the effect of plasma confinement by applying multi-polar magnetic field was investigated. High density plasmas on the order of 3.2 × 1011 cm?3 which is 50% higher than that obtained for the source without the magnetic field could be obtained at the pressure of 15 mTorr Ar and at the inductive power of 5,000 W with good plasma stability. The plasma uniformity <3% could be also obtained within the substrate area. When SiO2 film was etched using the double comb-type antenna, the average etch rate of about 2,100 Å/min could be obtained with the etch uniformity of 5.4% on the substrate area using 15 mTorr SF6, 5,000 W of rf power, and ?34 V of dc-bias voltage. The higher plasma density with an excellent uniformity and a lower rf antenna voltage obtained by the application of the magnetic field are related to the electron confinement in a direction normal to the antenna line. 相似文献
Plasma and electrical characteristics of an internal-type inductively coupled plasma source with a Ni–Zn ferrite module installed
near the antenna were investigated for different rf power frequencies of 2 and 13.56 MHz. Due to the lower heating of the
Ni–Zn ferrite module on the antenna for the operation at 2 MHz compared to the operation at 13.56 MHz, higher plasma density
and lower rf rms antenna voltage were resulted for the operation at 2 MHz in addition to more stable plasma characteristics.
By the application of 500 W of rf power to the source, a high plasma density of 8 × 1011 cm−3 which is about four times higher than that with 13.56 MHz could be obtained at the pressure of 10 mTorr Ar. When photoresist
etch uniformity was measured for the operation with 2 MHz by etching photoresist on a 300 mm diameter substrate using 10 mTorr
Ar/O2 (9:1) mixture, the etch uniformity of about 5.5% could be obtained. 相似文献
An internal-type linear inductive antenna, which is referred to as “double comb-type antenna”, was used as a large-area inductively
coupled plasma (ICP) source with a substrate area of 2,300 mm × 2,000 mm. The characteristics of the ICP source were investigated
for potential applications to flat panel display (FPD) processing. The source showed higher power transfer efficiency at higher
RF power and higher operating pressures. The power transfer efficiency was approximately 88.1% at 9 kW of RF power and a pressure
of 20 mTorr Ar. This source showed increasing plasma density and improved plasma uniformity with increasing RF power at a
given operating pressure. A plasma density >1.5 × 1011/cm3 and a plasma uniformity of approximately 11% was obtained at 9 kW of RF power and 15 mTor Ar using this internal ICP source,
which is applicable to FPD processing. 相似文献
Distance-of-flight mass spectrometry (DOFMS) is demonstrated for the first time with a commercially available ion detector—the IonCCD camera. Because DOFMS is a velocity-based MS technique that provides spatially dispersive, simultaneous mass spectrometry, a position-sensitive ion detector is needed for mass-spectral collection. The IonCCD camera is a 5.1-cm long, 1-D array that is capable of simultaneous, multichannel ion detection along a focal plane, which makes it an attractive option for DOFMS. In the current study, the IonCCD camera is evaluated for DOFMS with an inductively coupled plasma (ICP) ionization source over a relatively short field-free mass-separation distance of 25.3–30.4 cm. The combination of ICP-DOFMS and the IonCCD detector results in a mass-spectral resolving power (FWHM) of approximately 900 and isotope-ratio precision equivalent to or slightly better than current ICP-TOFMS systems. The measured isotope-ratio precision in % relative standard deviation (%RSD) was ≥0.008%RSD for nonconsecutive isotopes at 10-ppm concentration (near the ion-signal saturation point) and ≥0.02%RSD for all isotopes at 1-ppm. Results of DOFMS with the IonCCD camera are also compared with those of two previously characterized detection setups.
We demonstrate a new pathway for the synthesis of carbon nanohorns (CNHs) in a reactor by using inductively coupled plasma (ICP) and gaseous precursors. Thermal plasma synthesis allows the formation of different carbon allotropes such as carbon nanoflakes, hybrid forms of flakes and nanotubules, CNHs embryos, seed-like CNHs and onion-like polyhedral graphitic nanocapsules. In this study, pressure has the greatest impact on the selectivity of carbon nanostructures: pressure below 53.3 kPa favors the growth of carbon nanoflakes and higher pressures, 66.7 kPa and above, promotes the formation of CNHs. The ratio between methane and hydrogen as well as the global concentration of CH4?+?H2 inside the plasma flame are also crucial to the reaction. CNHs are formed preferentially by injection of a 1:2 ratio of H2 to CH4 at 82.7 kPa with a production rate of 20 g/h. The synthesis pathway is easily scalable and could be made continuous, which offers an interesting alternative compared to methods based on laser-, arc- or induction-based vaporization of graphite rods.
Capillary electrophoresis (CE) has become a powerful analytical technique for the separation of a variety of analytes ranging from small inorganic ions to large biomolecules such as proteins and nucleic acids. A selective and sensitive detector for CE has been one of the most important and challenging prerequisites for the growth of CE. On-column UV-Vis detectors are commonly used to determine the analytes separated by CE. However, these detectors are often not very selective. Other detection techniques such as mass spectrometry, laser induced fluorescence, amperometry, and inductively coupled plasma spectrometry have been investigated to provide a more sensitive and selective detection for the target analytes. However, relatively few studies have been published on the use of inductively coupled plasma atomic emission spectrometry (ICP-AES) as a means of detection in CE separation. 相似文献
In conventional inductively coupled plasma mass spectrometry devices, the sampler and skimmer are grounded. In this work, modest DC voltages (+ 10 to + 50 Vl are applied to either (or both) sampler and skimmer. Alternatively, the skimmer is biased, and the sampler is merely left floating. The latter arrangement improves sensitivity for Co+ by sixfold, provides nearly the same molar sensitivity for CO+, Rh+, and Ho+, and extends the upper end of the linear dynamic range to approximately 100 ppm. These changes to the interface do not affect the background perceptibly. The relationship between applied potential and the potential actually measured on the sampler and skimmer is also discussed. 相似文献