Electronic desorption of alkyl monolayers from silicon by very highly charged ions

Self-assembled alkyl monolayers on Si (111) were exposed to low doses of slow (v≈6.6×105 m/s≈0.3vBohr), highly charged ions, like Xe41+ and Th73+. Atomic force microscope images show craters from single ion impacts with diameters of 50–63 nm. Emission of secondary ions by highly charged projectiles was monitored by time-of-flight secondary ion mass spectrometry (TOF-SIMS). TOF-SIMS data give insights into the dependence of electronic desorption effects on the projectile charge state. We discuss the potential of highly charged projectiles as tools for materials modification on a nanometer scale.