Three-dimensional self-consistent simulation of silicon quantum-dot floating-gate flash memory device

We report on the simulation of single-electron charging operation of a silicon quantum-dot memory device using the self-consistent solutions of the Schrodinger and Poisson equations. We focus on the effects of the poly-wrapped gate on the onset of inversion. We show that the geometry of the control gate causes the inversion to occur on the vertical sides of the channel. The device experiences a strongly nonuniform threshold voltage shift as a function of the number of electrons in the dot to reach about 0.5 V when the floating gate quantum-dot is charged from empty to ten electrons.