Silicon Nano-Crystal Memories: Devices in the Limit of Conventional Miniaturization

Single transistor memory structure, with changes in threshold voltage exceeding &nearly. 0.25 V corresponding to single electron storage in individual nano-crystals, operating in the sub-3 V range, and exhibiting long term to non-volatile charge storage are reported. The structures avail the confinement and direct tunneling effects that take place at small dimensions - in silicon and silicon dioxide. As a consequence of Coulombic effects, operation at 77 K shows a saturation in threshold voltage in a range of gate voltages with steps in the threshold voltage corresponding to single and multiple electron storage. The plateauing of threshold shift, operation at ultra-low power, low voltages, and single element implementation utilizing current sensing makes this an alternative memory at speeds lower than of DRAMs and higher than those of E(sup3)PROMs, but with potential for significantly higher density, lower power, and faster read.