Fully Planar Impact Ionization (I 2)-RAM Cell With High-Performance and Nondestructive Readout

This work presents a fully planar, nondestructive readout, and high-performance impact ionization random access memory ( ${I}^{\,2}$ -RAM) cell having static random access memory (SRAM) characteristics. The proposed memory cell consists of a bipolar ${I}^{\,2}$ MOSFET (BIMOS) whose source region is shared with the drain region of a control gate (CG)-nMOS. The proposed ${I}^{\,2}$ -RAM offers excellent static characteristics, including write “1” (W1) time of ~0.5 ns, superior nondestructive readout time of ~0.4 ns, and sense margin (SM) of $\sim 242~\mu \text{A} / \mu \text{m}$ at room temperature (300 K). The proposed ${I}^{\,2}$ -RAM cell also shows a static retention time (RT) >3600 s at a lower supply voltage of ${V}_{\text{DS}} =1.1$ V for 300 K and 358 K temperatures. It additionally has a high read current ratio of $\sim 2\times 10^{9}$ and $\sim 4\times 10^{7}$ at temperatures 300 and 358 K, respectively. The proposed $I^{2}$ -RAM cell is promising candidate for embedded-RAM and high-performance applications.