Study on dopant activation and EOT impact in HKMG stacks using microwave annealing with different frequencies

Abstract

We have examined the dopant activation levels of various materials(Si, SiGe & Ge) annealed at two different frequency i.e., 2.45GHz and 5.8GHz microwave annealing (MWA) with the aim of identifying a material-targeted annealing method that will minimize the annealing process of high thermal budget. Furthermore, we also fabricated high-k/metal gate MOSCAP structure annealed at 2.45GHz and 5.8GHz MWA as the post-metallization annealing process. The results show that microwave annealing at 2.45GHz is more efficient than high frequency 5.8GHz MWA at 3000W in minimizing the interface trapped charged and the reduction in leakage current density. However, there is slight clear reduction in capacitance as the frequency increased to 5.8GHz resulting in increase of interfacial layer thickness. Due to undesirable effects such as Al diffusion into the dielectric layer, microwave annealing at 2.45GHz demonstrates great a potential candidate as a post-metallization annealing method for high-k/metal gate structures.