Large memory window and long charge-retention time in ultranarrow-channel silicon floating-dot memory

Abstract

We propose and demonstrate an ultranarrow-channel silicon floating-dot memory, in which the channel width is scaled to sub-10 nm. In the fabricated ultranarrow-channel memory, a larger threshold voltage shift has been observed than in the wide-channel memory. From numerical calculations, it turns out that this is caused by bottleneck regions that dominate the conductance of the whole channel in the ultranarrow-channel. Moreover, longer charge-retention time has been also obtained in the fabricated ultranarrow-channel memory. This can be explained by the nonlinear dependence of the threshold voltage shift on the number of electrons in the dots due to the classical bottleneck effect and the increase in the ground state energy of the channel due to the quantum confinement.