Characteristics Of Argon Plasma Research Articles

Fluid simulation of the superimposed dual-frequency source effect in inductively coupled discharges

Superimposition of dual frequencies (DFs) is one of the methods used for controlling plasma distribution in an inductively coupled plasma (ICP) source. The effects of a superimposed DF on the argon plasma characteristics have been investigated using a two-dimensional self-consistent fluid model. When both currents are fixed at 6 A, the plasma density drops with decrease in one of the source frequencies due to less efficient heating and the plasma uniformity improves significantly. Moreover, for ICP operated with superimposed DFs (i.e., 4.52 MHz/13.56 MHz and 2.26 MHz/13.56 MHz), the current source exhibits the same period as the low frequency (LF) component, and the plasma density is higher than that obtained at a single frequency (i.e., 4.52 and 2.26 MHz) with the same total current of 12 A. However, at superimposed current frequencies of 6.78 MHz/13.56 MHz, the plasma density is lower than that obtained at a single frequency of 6.78 MHz due to the weaker negative azimuthal electric field between two positive maxima during one period of 6.78 MHz. When the superimposed DF ICP operates at 2.26 and 13.56 MHz, the rapid oscillations of the induced electric field become weaker during one period of 2.26 MHz as the current ratio of 2.26 MHz/13.56 MHz rises from 24 A/7 A to 30 A/1 A, and the plasma density drops with the current ratio due to weakened electron heating. The uniformity of plasma increases due to sufficient diffusion under the low-density condition.

Measurement of the Current-Voltage Characteristics of Argon Plasma with a Tracking Probe

The current-voltage characteristics of argon plasma are investigated in the presence of noise using a tracking probe. It is revealed that at too close arrangement of the reference and measuring probes, the layer adjacent to the measuring probe influences differently the reference probe in different sections of the characteristic. For this reason, the number of triggering pulses changes during measurements of the current-voltage characteristics; therefore, the pulses should be counted when measuring the entire characteristic. Sequential ordering of the number of pulses per unit time demonstrates that probes insignificantly affect each other.

Determination of Characteristics of the Torch Discharge Plasma Burning in a Mixture of Atomic and Molecular Gases

The present article shows the results of temperature measurements of electrons and gas of the torch discharge burning in the mixture of argon and air. The study established the insignificant effect of added air on the characteristics of argon plasma and evaluated the conductivity of the plasma torch discharge burning in the mixture of argon and air.

Frequency dependent plasma characteristics in a capacitively coupled 300 mm wafer plasma processing chamber

Argon plasma characteristics in a dual-frequency, capacitively coupled, 300 mm-wafer plasma processing system were investigated for rf drive frequencies between 10 and 190 MHz. We report spatial and frequency dependent changes in plasma parameters such as line-integrated electron density, ion saturation current, optical emission and argon metastable density. For the conditions investigated, the line-integrated electron density was a nonlinear function of drive frequency at constant rf power. In addition, the spatial distribution of the positive ions changed from uniform to peaked in the centre as the frequency was increased. Spatially resolved optical emission increased with frequency and the relative optical emission at several spectral lines depended on frequency. Argon metastable density and spatial distribution were not a strong function of drive frequency. Metastable temperature was approximately 400 K.

1206 誘導結合プラズマリアクター内のプラズマパラメータ測定

The objective is to deepen the understanding of basic plasma properties in a high-density inductively coupled plasma (ICP) reactor. The experiment using a Langmuir probe, which is made of tungsten wire having length of 2.3 mm and diameter of 0.65 mm, is carried out to determine the characteristics of argon plasma. The axial and radial distributions of the plasma density, electron temperature, and plasma potential are measured. It was found that the electron density is in the range of 1.0×1010 to 1.0×1011 cm−3, electron temperature 4∼6 eV, and plasma potential 35∼45 V, respectively. These plasma parameters are spatially nonuniform in the axial direction; they depend on the distance between the plasma source and the measuring point. Next, etching of polycristalline silicon wafer by chlorine plasma is studied. The results obtained in this study indicate the effects of rf coil power, gas pressure, and substrate rf bias power on the distributions of the etch rate.

An rf sustained argon and copper plasma for ionized physical vapor deposition of copper

Langmuir probe, optical emission spectroscopy, and biased quartz crystal microbalance measurements were used to investigate an argon and copper plasma used for ionized physical vapor deposition of copper. Copper vapor generated by a magnetron sputter discharge is ionized upon passing through an argon discharge excited by an internal rf induction antenna. Argon plasma characteristics such as electron temperatures Te, plasma densities ne, and plasma and floating potentials Vp and Vf, were studied as a function of argon pressure and rf power. An increase of plasma density versus rf discharge power and argon pressure was observed. The radial profile of plasma density measured by a Langmuir probe reveals a peak ion density at the center of the rf antenna and an increase in the radial ion concentration gradient with argon pressure. The ratios of optical emission intensities from Cu+ ion and Cu neutral lines increase with rf discharge power and argon pressure. The biased quartz crystal microbalance measurements show an increase of both Cu+ ion flux and the ratio of Cu+ ion to Cu neutral fluxes with rf power and argon pressure; however, they also show a decrease of total Cu flux with increasing argon pressure.

疑似スパーク放電アルゴンプラズマ特性のレーザ計測

疑似スパーク放電アルゴンプラズマ特性のレーザ計測

Characterization of a multipole ion source for ion implantation

A design for a single-slit multipole source for ion implantation was investigated. Some of the general physical processes involved are reviewed. Argon plasma characteristics are described for four multipole configurations. Langmuir probe data was found to agree in form with continuity theory. In addition, we present scaling relations for secondary electron temperature and density. Superior performance was observed for gas and arc efficiencies compared to a similar Bernas-type source.