Dielectric tuning of negative capacitance in dual channel field effect transistors

Abstract

A transistor structure includes a semiconductor substrate; an NFET channel structure atop the substrate; a PFET channel structure atop the substrate; a first dielectric atop the PFET channel structure; a second dielectric atop the NFET channel structure; a shared internal metal gate atop the dielectrics; a shared ferroelectric layer atop the shared internal metal gate; and a shared external gate electrode atop the shared ferroelectric layer. The first and second dielectrics are doped with different metals that provide differing overall work functions for the PFET and the NFET. A method for making a transistor structure includes depositing a shared dielectric onto an NFET channel structure and a PFET channel structure, and converting the shared dielectric to a first high-k dielectric atop the PFET channel structure and a second high-k dielectric atop the NFET channel structure. The first high-k dielectric and the second high-k dielectric are doped with different metals.