Fabrication of single electron memory on atomically flat /spl alpha/-Al/sub 2/O/sub 3/ substrate made by AFM nano-oxidation process

The single electron transistor and the single electron memory with the planar structure were fabricated for the first time using the narrow oxidized Nb wires as tunneling junctions on the atomically flat niobium (Nb) metal surface that was on the atomically flat /spl alpha/-Al/sub 2/O/sub 3/ (1012) surface. The narrow oxidized Nb wires were formed using the AFM cantilever as an ultra-fine cathode. Owing to the atomically flat surface of the Nb metal, the uniformity and reproducibility of the oxidized line width and space, such as 10-15 nm were greatly enhanced and therefore the complicated tunnel junction structure for the memory could be fabricated.