A ferroelectric transistor gate structure with a ferroelectric gate and a high-k insulator is provided. The high-k insulator may serve as both a gate dielectric and an insulator to reduce, or eliminate, the diffusion of oxygen or hydrogen into the ferroelectric gate. A method of forming the ferroelectric gate structure is also provided. The method comprises the steps of forming a sacrificial gate structure, removing the sacrificial gate structure, depositing a high-k insulator, depositing a ferroelectric material, polishing the ferroelectric material using CMP, and forming a top electrode overlying the ferroelectric material.