Using E-Beam lithography, a 0.1㎛ active cross structure has been fabricated for single electron memory device. The orthogonal etching profile was obtained using RIE. The floating gate was made by etch back process and it could be made very small. The number of floating gate is depend on the active structure. If the active structure is cross, then 4 floating gates are formed in the region where active lines cross.
In this paper, it is estimated that 100~500 electrons in floating gate result in shift threshold voltage by 1V.