STABILIZATION OF FLATBAND VOLTAGES AND THRESHOLD VOLTAGES IN HAFNIUM OXIDE BASED SILICON TRANSISTORS FOR CMOS

摘要

The present invention provides a metal stack structure that stabilizes the flatband voltage and threshold voltages of material stacks that include a Si-containing conductor and a Hf-based dielectric. This present invention stabilizes the flatband voltages and the threshold voltages by introducing a rare earth metal-containing layer into the material stack that introduces, via electronegativity differences, a shift in the threshold voltage to the desired voltage. Specifically, the present invention provides a metal stack comprising: a hafnium-based dielectric; a rare earth metal-containing layer located atop of, or within, said hafnium-based dielectric; an electrically conductive capping layer located above said hafnium-based dielectric; and a Si-containing conductor.