Plasma system

A plasma system for plasma-enhanced chemical vapor deposition, the system comprising:

• a vacuum chamber,
• at least two electrodes,
• a substrate, and
• a matter to be ionized for depositing onto at least one desired surface of the substrate;
• and
• wherein the substrate comprises a tubular workpiece having two ends, with at least one of the two ends being an open end closed by a removable end cap in a manner that the vacuum chamber is defined by the workpiece and the cap;
• and wherein the work piece defines one of the electrodes with the other one of the electrodes being extended through the end cap and into the workpiece, and with at least one desired surface of the substrate being defined by an inner surface of the tubular workpiece;
• and
• wherein the at least two electrodes comprise a peripheral electrode formed by the tubular workpiece and a central electrode formed by said other one electrode;
• wherein the central electrode comprises a tubular electrode having a plurality of conduits in fluid communication to the vacuum chamber;
• and
• wherein the plurality conduits of the tubular electrode comprise at least one gas conduit for conducting process gas into the vacuum chamber, at least one precursor conduit for conducting a precursor matter into the vacuum chamber and at least one vacuum conduit for generating vacuum into the vacuum chamber;
• and
• wherein each of the gas conduit and the precursor conduit are provided with diffusion nozzles into the vacuum chamber and the vacuum conduit is provided with at least one suction port open into the vacuum chamber.