Sub-Micron Resolution of Localized Ion Beam Induced Charge Reduction in Silicon Detectors Damaged by Heavy Ions

Displacement damage reduces ion beam induced charge (IBIC) through Shockley-Read-Hall recombination. Closely spaced pulses of 200 keV Si ^{+ +} ions focused in a 40 nm beam spot are used to create damage cascades within 0.25 μm² areas. Damaged areas are detected through contrast in IBIC signals generated with focused ion beams of 200 keV Si ^{+ +} ions and 60 keV Li⁺ ions. IBIC signal reduction can be resolved over sub-micron regions of a silicon detector damaged by as few as 1000 heavy ions.