Experimental characterization of the plasma state as well as the neutral gas phase in low pressure radiofrequency discharges of oxygen/argon and HMDSO is presented. The plasma source (Copra by CCR Tecnology) produces a high density diffuse plasma in a cubic vacuum chamber (40 cm in size) driving an electrical discharge in reactive gas mixtures employing a resonant inductive coupling. The plasma state have been investigated by means of optical emission spectroscopy in order to identify the radicals formed in the dissociation processes during the discharge. Mass spectroscopy of the neutral and of the charged species has been performed too, directly sampling the gas-phase inside the discharge region, by a Hiden EQP1000 spectrometer. This allows to measure the absolute concentration of the neutral and charged gas-phase. We presents also results concerning the ion energy distribution which contributes with energetic particle bombardment to the growth and film formation processes.
We have studied the influence of the operating conditions (RF power, pressure, flow rate and oxygen/argon concentration) on the local gas-phase composition of the plasma state. The aim is to investigate the prevailing plasma interactions with material surface like those of polymers as PET. Such processes lead to the formation and the deposition of siloxane films, which are known for their important applicative uses.
Some results concerning the characteristics of the deposited film are presented too, describing their microscopic structure, composition and their potentially applicative properties.
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