US Patent 11784052 Dipole-engineered high-k gate dielectric and method forming same

A method includes forming an oxide layer on a semiconductor region, and depositing a first high-k dielectric layer over the oxide layer. The first high-k dielectric layer is formed of a first high-k dielectric material. The method further includes depositing a second high-k dielectric layer over the first high-k dielectric layer, wherein the second high-k dielectric layer is formed of a second high-k dielectric material different from the first high-k dielectric material, depositing a dipole film over and contacting a layer selected from the first high-k dielectric layer and the second high-k dielectric layer, performing an annealing process to drive-in a dipole dopant in the dipole film into the layer, removing the dipole film, and forming a gate electrode over the second high-k dielectric layer.