Vertically integrated unidirectional biristor

The unidirectional read-out characteristics of a two-terminal biristor are investigated through numerical simulations and experiments. The base doping profile in the biristor, which is analogous to an open-base bipolar junction transistor (BJT), is a key parameter to control both the multiplication factor and the common-emitter gain of the open-base BJT. The simulated results indicate that the asymmetric base doping produces a difference in the latch-up voltage according to the reading direction. A unidirectional conduction path is thereby implemented in a crossbar-array configuration that consists of only the two-terminal biristor. The experimental results based on a vertical structure with local charge injection support that the leakage path through the reverse read direction can be blocked by the asymmetric base doping structure with the selection of proper bias conditions.