A Novel Capacitorless DRAM Cell Using Superlattice Bandgap-Engineered (SBE) Structure With 30-nm Channel Length

We propose a novel SiGe superlattice bandgap-engineered (SBE) capacitorless dynamic random access memory (DRAM) cell with 30-nm channel length as a next-generation DRAM cell with high storage density and long retention time for practical implementation by 2-D technology computer-aided design simulation. The SBE capacitorless DRAM cell uses a common source structure and different metal layers for the top gate word line (WL) from the bottom gate WL to realize a 6F
²
feature size. Thanks to the Si
_0.8
Ge
_0.2
superlattice quantum well and silicon dioxide (SiO
₂
) physical barrier, we obtained 213 μA/μm for the sensing margin and about 10 ms for the retention time.