A method for manufacturing first and second transistors on a semiconductor substrate includes: depositing an interface layer on the semiconductor substrate; depositing a gate insulator layer on the interface layer; depositing a first ferroelectric layer on the gate insulator layer over a first region for the first transistor; depositing a metal gate layer on the gate insulator layer over a second region for the second transistor and on the first ferroelectric layer over the first region for the first transistor; and patterning the metal gate layer, first ferroelectric layer, gate insulator layer and interface layer to form a first gate stack for the first transistor which includes the metal gate layer, first ferroelectric layer, gate insulator layer and interface layer and a second gate stack for the second transistor which includes the metal gate layer, gate insulator layer and interface layer.