US Patent 12080553 Semiconductor device and method of manufacture

Structures and methods of forming semiconductor devices are presented in which a void-free core-shell hard mask is formed over a gate electrode. The void-free core-shell hard mask may be formed in some embodiments by forming a first liner layer over the gate electrode, forming a void-free material over the first liner layer, recessing the void-free material, and forming a second liner over the recessed void-free material.