Absolute UV and VUV emission in the 110–400 nm region from 13.56 MHz driven hollow slot microplasmas operating in open air

Abstract

We present absolute optical emission spectra in the 110-400 nm regions from radio-frequency-driven (13.56 MHz) hollow slot microplasmas operating in open air at atmospheric pressure. The term microplasma in our research refers to inter-electrode separation (100-600 µm) only, as electrode lengths are scalable from 1 to 30 cm. This creates an extended slot plasma and an associated afterglow plume as described herein. Spectra are presented for gas flows through the microelectrodes of argon and helium with small admixtures of hydrogen and nitrogen into open air. The spectra are discussed in terms of species origin and magnitude of the dominant emission lines. Atomic O and N lines dominate the 110-200 nm region, whereas, in the 200-400 nm region, NO, N 2 , N + 2 and NH molecular lines are strongest. The role of the N 2 (A 3 + u ) state in the open air microplasmas is discussed and the second positive system of molecular nitrogen (N 2 (C 3 g -B 3 g )), is used to measure the rotational (gas) temperature. Finally, we compare the efficiency and magnitude of light emission from the open air microplasmas with values attainable from commercial sealed mercury lamps in the UVB and UVC regions.

Mode transition in radio-frequency atmospheric argon discharges with and without dielectric barriers

“…4 Using radio-frequency ͑rf͒ excitation at which gas breakdown voltage is low 5 and plasma stability is robust, 6 large-area Ar rf APGDs have been achieved with unconventional electrodes such as microstructured electrodes, 7 multiple electrodes, 8 and microslot electrodes. 9 Recently, dielectric insulation of electrodes is also found beneficial. 10,11 By increasing the power input after gas breakdown, dielectrically insulated electrodes lead to largearea homogenous Ar APGD, whereas bare electrodes tend to evolve the argon discharge directly into constricted plasma.…”

Effect of light irradiation from inductively coupled Ar plasma on etching yields of SiO2film by CF3ion beam injections

“…Figure 3 shows a vacuum ultraviolet emission spectrum (110-290 nm) of the Ar ICP measured by a Seya-Namioka monochromator which was connected with the ICP device through the MgF 2 window. Line spectra of impurities (hydrogen H, carbon C, nitrogen N, and oxygen O) are seen in the 110-200 nm region while the emission is dominated by NO(γ) bands in the 200-290 nm region [7]. It is seen that there are no dominant line spectra of Ar in this region.…”

Effect of ultraviolet light irradiation on etching process of poly(methyl methacrylate) by ion beam injections

“…Figure 4 shows an emission spectrum of the Ar ICP measured by a Seya-Namioka monochromator in the vacuum ultraviolet region. Line spectra of impurities (hydrogen H, carbon C, nitrogen N, and oxygen O) are seen in the 110-200 nm region while the emission is dominated by NO(γ) bands in the 200-290 nm region [9]. It is seen that there are no dominant line spectra of Ar in this region (110-290 nm).…”