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

Abstract

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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> feature size. Thanks to the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.8</sub> Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.2</sub> superlattice quantum well and silicon dioxide (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) physical barrier, we obtained 213 μA/μm for the sensing margin and about 10 ms for the retention time.