Vertical Inner Gate Transistors for 4F2 DRAM Cell

In this article, we propose a novel cell transistor structure to facilitate the mass production of 4F
²
dynamic random access memory (DRAM). 3-D TCAD simulation results show that the proposed structure exhibits a better DRAM operation margin than the conventional vertical transistors. In particular, we confirmed that the failure mode due to the secondary effect of the floating body, the most pressing issue in relation to 4F
²
DRAM, is dramatically improved by adopting this structure.