Gate structure fabrication techniques for reducing gate structure warpage

Abstract

Gate fabrication techniques are disclosed herein for providing gate stacks and/or gate structures (e.g., high-k/metal gates) with improved profiles (e.g., minimal to no warping, bending, bowing, and necking and/or substantially vertical sidewalls), which may be implemented in various device types. For example, gate fabrication techniques disclosed herein provide gate stacks with stress-treated glue layers having a residual stress that is less than about 1.0 gigapascals (GPa) (e.g., about −2.5 GPa to about 0.8 GPa). In some embodiments, a stress-treated glue layer is provided by depositing a glue layer over a work function layer and performing a stress reduction treatment, such as an ion implantation process and/or an annealing process in a gas ambient, on the glue layer. In some embodiments, a stress-treated glue layer is provided by forming at least one glue sublayer/metal layer pair over a work function layer, performing a poisoning process, and forming a glue sublayer over the pair.