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 sl ow (upsilon approximate to 6.6 x 10(5) m/s approximate to 0.3 upsilon(Bohr) ) , highly charged ions, like Xe41+ and Th73+. Atomic force microscope imag es show craters from single ion impacts with diameters of 50-63 nm. Emissio n of secondary ions by highly charged projectiles was monitored by time-of- flight secondary ion mass Spectrometry (TOF-SIMS). TOF-SIMS data give insig hts into the dependence of electronic desorption effects on the projectile charge state. We discuss the potential of highly charged projectiles as too ls for materials modification on a nanometer scale. (C) 1998 American Vacuu m Society. [S0734-211X(98)13306-1].