Future Memory Devices - from Stacked memory, Gain memory, Single-electron memory to Molecular memory

Future possibilities for high speed memories will be discussed. In stacked memories, vertical MOSFETs are stacked onto MOSFETs. A 500 MHz 64 Mbit SRAM was demonstrated with reduced cell area, 60% of planar cell. PLEDM was proposed as a scalable DRAM gain cell which leads to single-electron memories. The transfer and detection of one electron was demonstrated using SOI structures at 4.2K. To achieve the room-temperature operations, nodes must be formed in atomic scale, and molecular memories should be investigated