Mode transitions in low pressure rare gas cylindrical ICP discharge studied by optical emission spectroscopy

Abstract

We report optical emission spectroscopy (OES) measurements in cylindrical inductively coupled plasma (ICP) discharges, focusing on E-to-H mode transition in rare gases (Ar, Kr, Xe). The discharge configuration is designed primarily as a radical source for treatment in a high vacuum system, but little is known about its characteristics. Two discharge modes are observed in Ar and Kr on increasing the power injected into the discharge (E-mode at low injected power and H-mode at high injected power). In this paper, we use OES measurements and calculations to infer rare gas discharge characteristics and mode transitions for this geometry in rare gases. It is shown that emission line intensity ratios from the OES signal of a level that is strongly coupled to a metastable state with one whose principal production mechanism is by direct excitation can be used to infer information about the electronic parameters of the discharge.

Plasma power measurement and hysteresis in the E–H transition of a rf inductively coupled plasma system

“…Similar behavior has been previously reported in emission line ratio measurements. 6,7 It is worth noting that at 25 and 50 mTorr ͑3.3 and 6.7 Pa͒, the metastable density also increases in E mode and then decreases in H mode with increasing power but no increase in metastable density at the E -H transition is observed ͓Fig. 3͑b͔͒.…”

Extreme-ultraviolet light generation in plasmonic nanostructures

“…Specifically, for inductively-coupled (IC) discharge plasmas, bistabilities have been studied for a long time, resulting in a large number of reports [97,98,99,100,120,121,119,122,123]. For example, Fig.…”

Optical Observation of Deep Bulk Damage in Amorphous Perfluorocarbon Films Produced by UV Photons Emitted from Low-Pressure Argon Plasma

“…The fluorescence spectrum of the sample exposed directly to the plasma showed a single broad peak ranging from approximately 500 to 700 nm, while no clear fluorescence peaks were detected from the sample prepared with a synthetic quartz window. Although emission spectrum of low-pressure argon plasma contains many peaks that are dominated by atomic Ar lines in the blue light region (due to 4s-5p transitions) and in the red/near-infrared spectral region (due to 4s-4p transitions) [33,34], few emission lines are emitted in UV and VUV region; resonance lines at 104.8 nm (ArI, 1s 0 -1s 2 ) and 106.7 nm (ArI, 1s 0 -1s 4 ) [10,11,14,16,[34][35][36]. Photon energies of these VUV emission lines are high enough (11.8 and 11.6 eV) to cause breakage of C-C, C-O and C-F bonds in the perfluorocarbon polymer, whose bond energies are 3.60, 3.64 and 4.57 eV, respectively [37].…”