MULTITUNNELING JUNCTION OF METAL DROPLETS FORMED ON CAF2 STEP EDGES IN A SELF-ASSEMBLING MANNER

One-dimensional metal droplet arrays of Ga and Al, the mean size of wh ich was smaller than 8 nm, were formed along step edges on the surface of epitaxial CaF2 film in a self-assembling manner. The two-step meth od by which Al and Ga were sequentially deposited to grow Ga/Al double layer droplets was examined, and it was shown to be suitable to reduc e gap spacing between neighboring droplets. A multitunnelling junction (MTJ) of Ga/Al droplets was formed by a two-step method and a MTJ dio de was fabricated by a conventional lift-off process. Current-voltage characteristic of the device showed a Coulomb staircase at 25 K and ro om temperature.