APPLICATION OF A MICROMACHINE SCANNING TUNNELING MICROSCOPE (MU-STM) FOR VACUUM TUNNELING GAP OBSERVATION

This paper reports the observation of the vacuum tunnelling gap betwee n two conductors of a scanning tunnelling microscope (STM), using a hi gh-resolution transmission electron microscope (TEM). A micromachine s canning tunnelling microscope (mu-STM) is made on a 2.5 mm(2) chip, by an advanced ultra-large scale integrated circuit (ULSI) technology wi th a minimum dimension of 0.4 mu m and alignment accuracy of 0.1 mu m. The mu-STM is designed to fit into a TEM sample holder for direct obs ervation of the tip apex, and the results demonstrate the possibility of analysing the tunnelling gap physics and material transport mechani sms at the tip apex.