On the Effect of Film Deposition on Probe Surface in Measurement by the Insulated Pulse Probe Method

Abstract

Calculation using a simple model showed that measurement by the insulated pulse probe method is essentially stable even if a contaminating film is deposited on the probe surface in reactive plasmas, in contrast with measurement by the conventional Langmuir probe method, which is very sensitive to changes in the probe surface condition. In the case where the contaminating film is conductive, the probe current response hardly changes. In the case where the contaminating film is insulative, the time constant of the probe current decay decreases with the accumulation of the contaminating film, which becomes an index of the thickness of the contaminating film. The reliability of measurement against the probe surface contamination is experimentally demonstrated in comparison with the conventional Langmuir probe method by exposure to plasmas containing oxygen and methane, respectively.

13C-NMR Spin Lattice Relaxation Time Observation on the Smectic A and Smectic C* Phases of a Chiral Smectic Liquid Crystal, (S)-4-(1-methylhexyloxycarbonyl)phenyl 4'-octyloxybiphenyl-4-carboxylate

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Then, the surface potential of the probe insulating layer deviates from V f0 and the voltage across the probe sheath changes according to the probe voltage. Consequently, the probe current is modulated by the probe voltage.…”

“…On the other hand, the insulated pulse probe (IPP) method [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]18) and the insulated modulation probe (IMP) method, 16,17) which are generically termed the insulated probe method, provide both basically stable measurement even in reactive plasmas and sufficient information on the plasma condition, and, in addition, do not require any sophisticated measurement equipment. Therefore, the insulated probe method is considered to be one of the most promising measurement tools for the monitoring of practical plasma processes.…”