A Tristate Switch Using Triangular Barriers

We demonstrate a new GaAs regenerative switching device with a double triangular barrier (DTB) structure, i.e., p⁺-i- δ(n⁺)-i- δ(p⁺)-i-n⁺, prepared by molecular beam epitaxy (MBE). Using the concept of sequential collapse of the internal barriers, two distinctive switching regions are established. First, a negative resistance region (S-type) is observed, followed by a positive resistance region (inverted N-shape) in between the switching behavior with the increase of applied bias. This device may have applicability for tristate logic circuits.