Induction coil, a plasma generator and a plasma generating method

An induction type plasma generating method using an induction coil formed by winding a wire on a surface of a virtual column wherein:

• the induction coil comprises first and second terminals serving as a winding start and a winding end respectively and wires which are connected to the first and second terminals respectively thereby to be formed into a coil part;
• the wires wound from the respective first and second terminal sides are wound on the virtual column surface so as to be located at symmetrical positions with respect to the virtual column surface;
• the wires are wound so as to intersect each other in an insulated state when wound a half turn and are thereafter wound again so as to be located at symmetrical positions with respect to the virtual column surface, the wires being repeatedly wound and thereafter connected to each other;
• and
• a high frequency power supply is connected to the first terminal and a variable capacitor is connected to the second terminal so that a potential at a middle point of the wires becomes approximately zero while both ends of the induction coil are at the same potential by the action of the variable capacitor,
• whereby a high frequency magnetic field is generated inside the induction coil by the high frequency power supplied to the induction coil, so that plasma is generated by action of the high frequency magnetic field while a potential of the plasma due to a capacitive current is rendered symmetrical.