Method and system for extracting ion beams composed of molecular ions (cluster ion beam extraction system)

An ion extraction system for extracting ions from an ion source, the ion extraction system comprising:

• an extraction aperture plate electrode forming one wall of an ionization chamber of an ion source, said extraction aperture plate formed with an aperture through which ions are transported;
• a suppression electrode disposed adjacent said extraction aperture plate, said suppression electrode formed with an aperture through which ions are transported, said aperture in said suppression electrode generally aligned with said aperture in said extraction aperture plate electrode;
• and
• a ground electrode disposed adjacent said suppression electrode, said ground electrode formed with an aperture, said aperture in said ground electrode generally aligned with said electrodes in said suppression electrode and said extraction aperture plate electrode, wherein said extraction aperture plate electrode formed with upper, lower and a main plate which includes an extraction aperture, said upper, lower and main plates electrically insulated from one another, said upper and lower portions adapted to receive electrical bias voltages for focusing said ion beam.