Investigation of different post HK annealing impact on HK film property and device performance

Abstract

HfO2 based high-permittivity gate dielectric has been introduced to CMOS logic device manufacturing since from 45nm node. However, these dielectrics are still under investigation and continuous optimization because of their relatively high oxygen vacancy concentration. Post Dielectric Annealing (PDA) after HK film may be a promising approach to reduce HK film trapped defect density and improve device performance as some literature reported recently. In the present work, different annealing conditions were applied on interface layer (IL)/HfO2 stack films, including soak annealing, spike annealing, and flash lamp based Milli-Second Annealing (MSA). Both blanket wafer and MOSCAP wafer characterization results show post HK MSA is an effective method to repair HK intrinsic defect, like oxygen vacancy, while it also beneficial for improving the Si/IL, IL/HK interface quality.