Conical theta pinch plasma for deposition of thin polymer films

Abstract

A conical theta pinch coil has been used to deposit a thin film of polymer onto a potassium bromide (KBr) substrate using a monomer gas of C/sub 2/H/sub 2/ (acetylene). The plasma source consisted of a one turn conical theta pinch coil wrapped around a 10-cm ID Pyrex vacuum vessel. The coil was energized by a 1.9- mu F capacitor charged to 20 kV (stored energy approximately=380 J). The damped sinusoidal current had a frequency of 230 kHz and a peak amplitude of 55 kA. The duration of light emission from the plasma was about 30 mu s. After 80 discharges, the polymer film was analyzed with a scanning electron microscope (SEM) and a Fourier transform infrared (FTIR) spectrometer. The FTIR spectrum showed that there were carbon-to-hydrogen bonds and carbon-to-carbon double bonds in the deposited film. The SEM measurements indicate that the film was about 10000 AA thick, showing that the conical theta pinch plasma was depositing a polymer film at the rate of 125 AA per discharge. >