A Capacitorless Double Gate DRAM Technology for Sub-100-nm Embedded and Stand-Alone Memory Applications

A capacitorless, asymmetric double gate DRAM (DG-DRAM) technology is presented. Its double gate, thin body structure reduces dopant fluctuation effects, off-state leakage, and disturb problems. The cell's large body coefficient amplifies small gains of body potential into increased drain current. Experimental measurements of DG-DRAM were made using recessed channel SOI n-MOSFETs. No significant degradation in programming, retention, and read behavior was observed after 10¹¹ cycles. Cell geometry, operating voltages, and material quality should be considered for DG-DRAM in embedded and stand-alone applications. The feasibility of DG-DRAM in future high density CMOS memories depends on issues such as manufacturability, soft error reliability, and tail bit distribution.