Design of two-terminal-electrode vertical thyristor as cross-point memory cell without selector

Abstract

We proposed a two-terminal-electrode vertical thyristor and investigated its suitability as a cross point memory cell without a selector from the viewpoints of p(+)- and n(+)-base region width and a vertically stacked doped-epitaxial-Si layer structure such as p(++)-emitter/n(+)-base/p(+)-base/n(++)-emitter or n(++)-emitter/p(+)-base/n(+)-base/p(++)-emitter. The proper p(+)- and n(+)-base-region width (i.e., 160 nm) and p(++)emitter/n(+)-base/p(+)-base/n(++)-emitter layer structure could enable the development of a cross-point memory cell using the half bias concept by preventing misfit dislocations at the junctions between the n(++)-emitter and p(+)-base or n(+)-base and p(++)-emitter. It was also found that generation of the misfit dislocations originating from B or P atom segregation at junctions during doped-Si epitaxial-layer growth enhanced the strain at the junctions. The misfit dislocations at the junctions were produced when the strain at the junctions was greater than similar to 4 x 10(-4).