Useful yields of organic molecules under dynamic SIMS cluster bombardment

摘要

Useful yields have been measured for a series of organic compounds using Ar+, SF5+ and Bi3+ primary ion bombardment under high dose (>1013 ions/cm 2) SIMS sputtering conditions on both magnetic sector and ToF-SIMS instruments. A precision inkjet deposition system was used to produce well defined arrays of microdrops on silicon with each deposit containing a known number of analyte molecules. The individual deposits were sputtered until consumed while monitoring the integrated characteristic molecular secondary ions for each analyte. The ratio of integrated counts to the number of molecules in the deposit defines the useful yield of the experiment. Measured useful yields varied from 1 × 10-2 to less than 1 × 10-8 depending on the compound examined, the probe beam used and the instrument configuration.