A room-temperature single-electron memory device using fine-grain polycrystalline silicon

The first room-temperature operation is demonstrated of a single-electron memory device, in which an electron represents one-bit information. This is made possible due to our new one-transistor memory configuration (conventionally three circuit elements are needed), which has very high charge sensitivity. Another new technique, which stabilizes the one-electron stored state, is ultra-thin (4 nm) poly-Si film for the active region, in which an array of 10-nm grains are naturally formed. In the fabricated poly-Si TFTs a single electron is systematically stored (or "written") with every 15-V gate-voltage increase, and the number of stored electrons is counted (or "read") by the quantized threshold-voltage shift. The single-electron memory provides a new non-volatile RAM, which is very suitable for mobile computers/communicators.<>