A single-electron stochastic associative processing circuit robust to random background-charge effects and its structure using nanocrystal floating-gate transistors

摘要

A new single-electron circuit using the unique features of single-electron devices is proposed, based on a basic strategy and circuit architecture for achieving large-scale integration. A unit circuit consisting of a single-electron transistor and a capacitor operates as an exclusive-NOR gate by the Coulomb blockade effect, and its transient behaviour is stochastic due to electron-tunnelling events. Using this unit circuit, a stochastic associative processing circuit is proposed, based on a new information-processing principle where the association probability depends on the similarity between the input and reference data. This circuit can be constructed by using a silicon nanocrystal floating-gate structure in which dots are regularly arranged on a gate electrode of a MOSFET. The simulation results of a simple digit pattern association demonstrate the successful stochastic operation. The background-charge effects on the proposed circuit are analysed and simulated, and it is shown that the circuit is much more robust to such effects than the conventional single-electron logic circuits.