Ferroelectric transistors with improved characteristics at high temperature Available to Purchase

We report on the temperature dependence of ferroelectric metal-oxide-semiconductor (MOS) transistors and explain the observed improved characteristics based on the dielectric response of ferroelectric materials close to the Curie temperature. The hysteretic current-voltage static characteristics of a fully depleted silicon-on-insulator transistor, with 40 nm vinylidene fluoride trifluorethylene, and 10 nm $SiO2$ gate stack, are measured from 300 to 400 K. In contrast with conventional MOS field effect transistors (MOSFETs), the subthreshold swing and the transconductance show, respectively, a minimum and a maximum near the Curie temperature (355 K) of the ferroelectric material. A phenomenological model is proposed based on the Landau–Ginzburg theory. This work demonstrates that a MOSFET with a ferroelectric layer integrated in the gate stack could have nondegraded or even improved subthreshold swing and transconductance at high temperature even though the hysteresis window is reduced. As a consequence, we suggest that for ferroelectric transistors with appropriately designed Curie temperatures, the performance degradation of logic or analog circuits, nowadays operating near $100°C$⁠, could be avoided.