Low-Cost and Highly Heat Controllable Capacitorless PiFET (Partially Insulated FET) 1T DRAM for Embedded Memory

A body-tied partial-insulated FET (PiFET) one-transistor (1T) DRAM having good heat immunity for embedded memory is proposed in this paper. PiFET structure using partially insulated oxide (PiOX) formed on bulk wafer can act as a 1T DRAM by applying a negative back bias. The memory shows a good ldquo0rdquo-state retention characteristic due to reduced electric field and heat dissipation path. The body-tied PiFET provides a wider design window and flexibility to control retention characteristics than does silicon on insulator (SOI) FET. To evaluate the improvement of retention characteristics, we suggest a new retention degradation mechanism of 1T DRAM. In this paper, we suggest the possibility of 1T DRAM´s fabrication having good heat immunity.