Applications of sawtooth doping superlattice for negative-differential-resistance devices fabrication

Abstract

A negative‐differential‐resistance (NDR) device with a sawtooth‐doping‐superlattice (SDS) structure, prepared by molecular‐beam epitaxy, has been fabricated and demonstrated. The SDS structure contains two different δ‐doping superlattices. Multiple‐state NDR performance is observed due to the strong field effect and avalanche multiplication. Theoretical analysis for a single δ‐doping structure and a SDS structure is carried out to study the two‐dimensional electronic properties of quantized states and minibands. An S‐shaped NDR device with the SDS structure is fabricated and studied. The δ‐doping density profile provides a barrier height variation in the superlattice which influences the transport properties. With adequate design of device parameters, e.g., superlattice periods and doping density, the proposed structure may provide good potential for multiple‐state logic circuit applications.