Threshold ionization mass spectrometry study of singlet molecular oxygen in the…

Threshold ionization mass spectrometry (TIMS) has been used to measure the excited molecular oxygen states O2 (1g) and O2 (1+g ) during plasma-assisted chemical vapour deposition of tin oxide (SnO2) thin films. The latter, composed of nanosized features, was deposited by feeding in a mixture of Ar, O2 and tetramethyltin (Sn(CH3)4 or TMT) in a capacitively coupled RF discharge reactor.

Surface loss coefficients of CFx and F radicals on stainless steel

The surface loss coefficients of CFx (x51 – 3) and F radicals have been measured on the stainless steel walls of the differential pumping systems of a plasma reactor. This measurement is made by comparing the beam to background signal ratio of the radicals measured by appearance potential mass spectrometry.

Quantification of a Radical Beam Source for Methyl Radicals

A radical beam source for methyl radicals (CH3) was characterized applying ionization-threshold mass spectrometry. The beam source is based on thermal dissociation of methane (CH4) or azomethane (N2~CH3!2! in a heated tungsten capillary. A flux of (361)31013 cm22 s21 CH3 radicals is produced using methane as precursor gas and a capillary temperature of 1650 K.