DEPOSITION OF CLUSTER IONS ON SOLID SURFACE AND OBSERVATION BY STM: DEVELOPMENT OF APPARATUS

摘要

We developed and constructed an apparatus for cluster deposition on a solid surface, which is observed by an SPM. Cluster ions were prepared in a gas-aggregation source in which atomic ions were produced by a magnetron sputter-source, and were aggregated in cooled helium gas. A size-selected cluster ion by a quadrupole mass filter was deposited on a surface maintained at 77 K with a collision energy of 1 eV-30 keV at a pressure of 1x10~(-7) Pa or less. STM measurements were performed at a pressure less than 4x10~(-9) Pa and at a temperature of 6 K. At the first place, we generated a copper cation with a current of 15 nA. The full width at half maximum (FWHM) of its translational energy was measured to be 2 eV by a retarding potential method. We obtained STM images of bare silicon and graphite surfaces with atomic resolution at a temperature of 9-300 K.