Generator

A generator comprising:

• a plasma production tube made of a dielectric at least on a surface of the plasma production tube;
• an antenna that includes a linear conductor and a dielectric that coats the conductor;
• a high-frequency power supply connected to the antenna;
• and
• a gas supply unit that supplies a gas for generating radicals or ions to an interior of the plasma production tube,
• wherein one end of the plasma production tube is connected to the gas supply unit,
• wherein the other end of the plasma production tube is a discharge port for radicals or ions produced inside the plasma production tube,
• wherein both ends of the antenna are guided outside the plasma production tube from the one end of the plasma production tube and are connected to the high-frequency power supply,
• wherein a high-frequency power is supplied from the high-frequency power supply to the antenna thereby generating an inductively coupled plasma inside the plasma production tube to generate radicals or ions from the gas,
• wherein the antenna is disposed to extend to a vicinity of the other end of the plasma production tube,
• wherein the antenna is disposed in a groove formed in an axial direction on an inner surface of the plasma production tube at least in a portion in a range from the one end to the vicinity of the other end of the plasma production tube, and
• wherein the antenna is disposed in a groove formed in a circumferential direction on an inner surface of the plasma production tube at least in a portion of the vicinity of the other end of the plasma production tube.