Switching in Nanoscale Hafnium Oxide-Based Ferroelectric Transistors

The recent advent of ferroelectricity in thin hafnium oxide films has enabled an unprecedented scaling of ferroelectric field-effect transistors (FeFETs) based on this material. However, the small-area devices, which have the channel length of only a few tens of nanometers, show some striking performance differences when compared to the large-area ones. In this chapter, the switching of these nanoscale FeFETs will be investigated. In particular, novel switching phenomena will be pointed out, including the abrupt and stepwise switching transitions, the appearance of switching stochasticity and the evidence for the accumulative switching upon identical voltage excitations. These properties not only provide new and useful insights for memory applications but also set the basis for exploiting FeFETs for novel applications, such as neuromorphic and stochastic computing.