Investigations of impact ionization phenomena in advanced transistors and speed-power improvement of BiMOS SRAM cells based on reverse base current effect

Abstract

The experimental investigations of base reverse current of integrated Si polysilicon emitter bipolar transistor and its multiplication coefficients ( M−1) vs. U cb at different I E when the device is driven at constant emitter currents are represented. Current crowding effect induced by impact ionization in advanced Si transistors and intrinsic complex instabilities and limitations affecting multiplication coefficients under variable high electric fields at low and high emitter current densities are analysed. The speed-power potential and limitations of high-density memory cells based on reverse base current effect are discussed. Speed-power possibilities and limitations of scaled down BiMOS SRAM cells are examined using numerical simulation of their capabilities to work in a memory system at different conditions.