A combined apparatus of scanning reflection electron microscope and scanning tunneling microscope

A scanning reflection electron microscope (SREM) combined with a scanning tunneling microscope (STM) has been developed for the purpose of nanoscale structure fabrication under ultrahigh vacuum conditions. A STM unit consists of a piezoelectric tube scanner and an inch runner for coarse and fine approach of a STM tip. A sample holder and the STM unit have six drive axes relative to an electron gun for simultaneous observation by SREM and STM. Energy-dispersive x-ray spectroscopy equipment is also installed for surface sensitive elemental analysis. It has been demonstrated that on a Si(111)7×7 surface atomic steps and 7×7 unit, cells can be observed in the SREM and STM images, respectively, and that surface elements with less than 1 ML thickness are detectable.