What are the integration processes of high-k metal gates?

High-k metal gate integrates the technology of reducing gate leakage current and improving device reliability. With the decrease of transistor size, the thickness of gate oxide layer and the distance between source and drain further decrease, and the gate leakage current and the leakage current between source and drain increase sharply, so the traditional SiO _ 2 and SiON can no longer meet the needs of industry. In order to overcome these problems, only high-k dielectric with high dielectric constant can be used to replace the traditional silicon dioxide dielectric. High-k gate dielectric can increase the physical thickness of gate dielectric while keeping the gate capacitance unchanged, thus achieving the dual purposes of reducing gate leakage current and improving device reliability.