ION SOURCE APPARATUS AND ELECTRON ENERGY OPTIMIZING METHOD FOR THE SAME TO DECREASE THE NUMBER OF UNNECESSARY HYDROGEN IONS TO IMPROVE RATE OF GENERATING HEAVY IONS

摘要

PURPOSE: An ion source apparatus and an electron energy optimizing method for the apparatus are provided to decrease the number of unnecessary hydrogen ions to improve the rate of generating heavy ions by arranging an antenna and a magnet in a plasma chamber without placing a magnetic filter in the plasma chamber. CONSTITUTION: An ion source apparatus(1) includes a plasma chamber(2), an antenna(10), a plurality of magnets(6), and an extraction electrode system(3). The plasma chamber includes an inlet(4) through which an ion source gas is supplied. The antenna generates plasma in the plasma chamber using high-frequency voltage provided by a high frequency output unit(17). The magnets are arranged on the wall of the plasma chamber to form a sharp magnetic field that restrains the plasma. The extraction electrode system includes a plurality of electrodes(11,12,13,14) for extracting ion beams from the plasma.