A phase-space-compressing, mass-selecting beamline for hyperthermal, focused ion beam deposition

We have developed an ion beamline for hyperthermal ion-surface collisions that incorporates a phase-space compressor to improve the focusability/current density of the ion beam in the 1–10 eV deposition energy range. In essence, collisional damping is used to substantially improve the brightness of the ion source. In addition to the focusing behavior, the beamline also accomplishes mass selection, source-target pressure reduction of >1010, confinement of the beam to avoid space charge spreading, and hyperthermal energy beam transport. For our application the requirement is moderately tight (100 s of microns) focusing at hyperthermal energies (1–100 eV), but the principle should also be applicable to improving spot sizes/current densities at higher energies.