Langmuir probe measurements in commercial plasma plants

Abstract

W e developed ana tested a LangmJir aouble-probe system s. . taole for measJrement in industr'al environments. where quic6 and easy-to-nandle methods are requ'red. Data acquisition and calculation of plasma parameters are cantro led ay a personal computer. An evalLation agorithm 's presented and its properties are brielly dscussed. SJccessful operat'on of !ne system can ae proved :n a var:ery of different plasma configurations, namely 'n raaiolreqJency driven, pulsed direct current ana microwave plasmas. Typical measuements and the conclusions that have been arawn are presentea. Plasma aensit'es were in tne range 108-10'3cm-3. From the ena user's point of v:ew the main appl'cation areas are tro-be-snoot:ng, on-line process control and plasma source characterization auring the aevelopment stages of a plasma plant.

Optical emission spectroscopy of CO2 glow discharge at low pressure

“…From the measured experimental current-voltage characteristic curve [12,13] obtained by the double Langmuir probe at a pressure of 0.8 mTorr of CO 2 , it possible to get electron temperature and ion density [12,13] (Fig. 4).…”

“…4). The electron temperature and ion density were obtained fitting the theoretical curve to the experimental data [12,13]. That procedure gives an electron temperature of T e = 8.53 eV and an ion density of n i = 7.11 x 10 9 cm -3 .…”

Measurements of electron temperature and ion density in an ac pulsed CO plasma study

“…From the position of the extrema in the second derivative of the characteristics curve, the electron temperature is calculated [10][11][12]. Then a theoretical curve is fitted to the entire measured experimental current-voltage characteristic curve [10,11] by adjusting only the ion density ( ) i n . This evaluation procedure gave an electron temperature of T e = 2.15 eV and an ion density of n i = 1.24 x 10 10 cm -3…”

Magnetic field effects on secondary electron emission during ion implantation in a nitrogen plasma

“…17 The voltage between the probe's tips was swept from −90 to + 90 V, and the I-V characteristic curve ͑with about 300 points in this voltage range͒ was monitored. Density and temperature radial profiles were determined at the implantation target's longitudinal position in the presence of the Faraday cups.…”