Devices and methods for electrostatic ion beam deflection and filtration

A device for electrostatic deflection of an ion beam, wherein the device comprises:

• an entrance aperture to allow the ion beam to enter the device;
• an exit aperture to allow the ion beam to exit the device;
• a first set of electrodes disposed above an ion beam path, wherein the first set of electrodes comprises:
• a first entrance-end electrode positioned closest, of the first set of electrodes, to the entrance aperture;
• and
• a first exit-end electrode positioned closest, of the first set of electrodes, to the exit aperture, wherein the first entrance-end electrode is biased to within 5% of an electric potential to which the first exit-end electrode is biased;
• and
• a second set of electrodes disposed below the ion beam path, wherein the second set of electrodes comprises:
• a second entrance-end electrode positioned closest, of the second set of electrodes, to the entrance aperture;
• and
• a second exit-end electrode positioned closest, of the second set of electrodes, to the exit aperture, wherein the second entrance-end electrode is biased to within 5% of an electric potential to which the second exit-end electrode is biased, and
• wherein the first set of electrodes comprises a different number of electrodes than the second set of electrodes.