> Leakage current is a well-known problem in these kinds of transistors, “so integrating an innovative ferroelectric layer into the gate stack to address this has clear promise,” says Aaron Franklin, an electrical engineer at Duke University, in Durham, N.C. “It certainly is an exciting and creative advancement.”

I'm wondering if this will eventually transition out of power electronics into other sorts of electronics. Sounds like they've got their next five years planned just looking at power electronics though.

Hafnium and zirconium dioxide are CMOS foundry compatible.

Hafnium dioxide has been the gate dielectric for MOS transistors in all dense CMOS processes for a couple of decades. It is certainly used in whatever smartphone or computer you have.

With the former gate dielectric, silicon dioxide, it was impossible to make MOS transistors as small as in modern processes, because it has a too low dielectric constant, which would have required impossibly thin gate layers (for high enough gate capacitances).

Hafnium dioxide has a much higher dielectric constant, allowing to achieve the same gate capacitance at a manageable gate thickness.

The chemical behaviors of hafnium and zirconium are almost identical, their similarity being as great as between rare-earth elements, but for the dielectric behavior of their oxide the substitution of a fraction of the hafnium with zirconium and appropriate treatments can make the oxide ferroelectric.

Many great applications have been proposed for ferroelectric Hf-Zr dioxide already for some years, but I have not heard of any commercial device. The reason is not any compatibility problem with CMOS processes, but I believe that it might be hard to obtain reproducible ferroelectric properties, as they might vary a lot depending on the exact parameters of the manufacturing steps.