ION SOURCE, CLEANING METHOD IN ION PROCESSING PROCESS

PROBLEM TO BE SOLVED: To carry out cleaning during a processing process for an ion chamber. SOLUTION: An ion source 12 includes a plasma chamber formed by chamber walls 112, 114, 116 determining a boundary for an ionization zone 120, a dopant gas generating source 66 and a first mechanism portion 68 for introducing ionizable dopant gas into the plasma chamber, a cleaning gas generating source 182 and a second mechanism portion 184 for introducing cleaning gas into the plasma chamber, and an exciter 130 for supplying energy to the dopant gas and the cleaning gas to generate plasma inside the plasma chamber. The cleaning gas is separated, ionized components are separated from the dopant gas, and reaction with the ionized components is conducted so as to prevent the components contained in the dopant gas from being deposited on the chamber walls 112, 114, 116.