Development of a radio-frequency glow discharge source with integrated voltage and current probes

Electrical measurements at radio frequency glow discharges for spectroscopy

“…To sputter a thick insulating material (d s N 2 mm) with a low dielectric constant (silica glass, ε r = 3.1), we estimated in Ref. [62] that the amplitude of the RF voltage (f = 3.37 MHz) at the electrode should exceed U E N 3500 V. To measure thin layers the RF generator voltage should stabilize very fast. To resolve a surface layer with a sheath thickness of 1 nm at a sputtering rate of 100 nm/s the voltage should be stabilized in less than 10 ms.…”

“…Rohde & Schwarz, FSL3) or a modern oscilloscope with a Fast-Fourier-Transformation [40,62]. At resistive loads (Match, 50 Ω) fixed frequency RF generators usually supply a sinusoidal voltage with a total harmonic distortion k E b 1%.…”

“…6 shows a simplified equivalent circuit of a free running RF generator. The parallel resonance circuit of L r and C r is powered by the triode T O [40,62]. The impedance of the glow discharge source including power transmission cable and discharge is parallel to L r and C r and determines its resonance frequency (3.37 MHz).…”

Radiofrequency glow-discharge devices for direct solid analysis

“…When current-voltage characteristics for different conducting and insulator sample materials, pressures, and voltages were presented for such a system, estimated errors in voltage, current, and power measurement were smaller than 8% [29]. Interest in, and the feasibility of, using a control mode based on constant "effective power-voltage" to operate the rf-GD-OES has been evaluated [30].…”

“…For this reason an rf-GD with integrated voltage and electrical current probes has recently been described [29]. When current-voltage characteristics for different conducting and insulator sample materials, pressures, and voltages were presented for such a system, estimated errors in voltage, current, and power measurement were smaller than 8% [29].…”