Characteristics of a GaAs metal-n⁺-v-δ (p⁺)-v-n⁺ switch

A new GaAs switching device consisting of a metal-n⁺-v-δ(p⁺)-v-n⁺ structure has been fabricated and demonstrated. An InGaAs delta-doped quantum well was employed to provide the potential barrier for carrier transport and improve the confinement effect of holes. When sufficient anode-to-cathode voltage V_AK was applied to this device, an interestingly double S-shaped negative-differential-resistance (NDR) characteristic was obtained at the temperature lower than -40°C. This was caused by the sequential avalanche multiplications in the n^--GaAs (v) layer near the anode electrode and the Schottky-semiconductor (M-S) junction. However, only a single S-shaped NDR phenomenon was observed at higher temperatures due to the poor carrier confinement effect of holes in the delta-doped quantum well. The influence of temperature on the device performance was also investigated. From experimental results, it is known that the environmental temperature plays an important role on the NDR performances. Consequently, if device parameters are appropriately adjusted, this device shows a good potenital for multiple-value logic circuit applications.