Oxygen rf glow discharges between parallel plates were numerically analyzed by using the relaxation continuum model. The result at a frequency of 13.56 MHz, sustaining voltage of 150–350 sin ωt V, pressure of 0.15–1.0 Torr, and stainless steel surface, shows that O2(a1Δg) has a number density that is an order of magnitude larger than that of atomic oxygen. The plasma density as a function of pressure has a maximum at about 0.2 Torr, and decreases with increasing pressure due to the increase in the net rate of associative detachment from O− by O2(a1Δg). The comparison between the discharges in two surface materials, stainless steel and copper, indicates that the number densities of O2(a1Δg) and atomic oxygen strongly depend on the surface loss probability, and that consequently the plasma density is also changed by replacing the surface material.

Plasma potentials of 13.56 MHz rf argon glow discharges in a planar system J. Vac. Sci. Technol. A 3, 638 (1985); 10.1116/1.572968Plasma potentials of 13.56MHz rf argon glow discharges in a planar system FIG. 6. Avenged power density, plasma density, and phase difference hetwecn l(r) and V(t) as a function of V. at ~2 =U.S Tort; and.f= 13.56 MHz.

Using the relaxation continuum (RCT) model, numerical analysis of oxygen rf glow discharges between parallel plates with laser irradiation parallel to the electrode was performed. The oxygen discharge sustained by a sinusoidal wave voltage at a frequency of 13.56 MHz, amplitude of 200-230 V and pressure of 0.5-1.0 Torr is irradiated by the laser with a power of 300 W, width of 2 mm and wavelength of 0.53 µm. Under these conditions, laser-induced photodetachment occurs with a large enough rate to affect the discharge structure significantly. When the plasma is irradiated continuously, the number density of ions in the incident region decreases by about 30%. The electron number density and the flux in the discharge when the pulsed laser is turned on and off every ten rf cycles, show prominent temporal variation with the variation of the electric field. Electron cooling is enhanced during the laser irradiation.

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The influence of the electrode material on O2 radio-frequency discharge structure is investigated using the relaxation continuum (RCT) model. The discharges considered in this study are self-sustained between parallel plates with spacing of 2 cm at 13.56 MHz. The spatiotemporal discharge structure for the pressure of 1.0 Torr and the sustaining voltage of 100–300sin ωt V is calculated. The results are discussed for two types of material differing in the surface recombination probability of atomic oxygen γ. When γ is changed from 0.015 to 0.001, the number density of atomic oxygen increases and the distribution has less spatial dependence. As a result, the rate of the electron detachment caused by the collision between O- and O increases, and the plasma density and the density ratio of the negative to positive ions decrease. The change of the material surface also affects the fluxes of positive ions and atomic oxygens to the electrode at a fixed sustaining voltage. The influence of the surface on the dissipated power is also discussed.