A novel superlattice band-gap engineered (SBE) capacitorless DRAM cell with extremely short channel length down to 30 nm

We propose a novel SiGe superlattice band-gap engineered (SBE) capacitorless dynamic random access memory (DRAM) cell with the 30 nm channel by the 2D TCAD simulation. The SBE capacitorless DRAM cell used a common source structure and different metal layers for the top gate word line from the bottom gate word line to realize the 4F² (0.0036 μm²) feature size. From the 2D TCAD simulation of the SBE capacitorless DRAM cell, thanks to both the Si_0.8Ge_0.2 quantum well and SiO₂ physical energy barrier, we obtained the sensing margin of 6.4 μA and the retention time of 15 msec.