Method and Chamber for Inductively Coupled Plasma Processing for Cylinderical Material With Three-Dimensional Surface

A method of plasma processing a cylindrical workpiece with a three-dimensional profile using a plasma processing reactor comprising:

• a grounded vacuum chamber made of a conductive material and having an outer wall;
• workpiece bearing means connected to the outer wall of the vacuum chamber in such a fashion as to be electrically insulated from the vacuum chamber;
• at least one cylindrical workpiece mounted around the workpiece bearing means, the cylindrical workpiece being connected to an external RF power source through an impedance matching network at one end and a terminating capacitor at the other end;
• and a cylindrical gas shower electrode disposed inside the vacuum chamber so as to surround the workpiece, the method comprising the steps of:
• (a) applying RF power to the cylindrical workpiece through the impedance matching network;
• (b) forming plasma inside the vacuum chamber through generation of resonance by the applied RF power;
• (c) creating a negative DC selfbias on the workpeice due to a difference in mobility of ions and electrons;
• and
• (d) processing the workpiece using plasma ions accelerated within the formed plasma