Focused Ga+ ion milling of lightly Si-doped, n-type Ga2O3 was performed with 2-30 kV ions at normal incidence and beam currents that were a function of beam voltage. The electrical effects of the ion damage were characterized by Schottky barrier height and diode ideality factor on vertical rectifier structures comprising 10 μm epitaxial n- Ga2O3 on n+ Ga2O3 substrates, while the structural damage was imaged by Transmission Electron Microscopy. The forward current-voltage characteristics showed significant deterioration at 5kV. The I-V characteristics no longer showed rectification for the 30kV condition. Subsequent annealing up to 400°C produced substantial recovery of the I-V characteristics for all beam energies and was sufficient to restore the initial ideality factor completely for beam energies up to 5kV. A remarkable reduction of dislocations can be observed in 30 kV ion exposed sample after annealing at 400°C.