Demonstration Highly Scalability of Ultra-Thin EOT HfO2-ZrO2-HfO2 Gate Stacks With 25 nm Lg FinFET for Advanced CMOS Technology

We demonstrate the high scalability of equivalent oxide thickness (EOT) scaled HfO2-ZrO2-HfO2 (HZH) gate stacks based on FinFETs with a physical gate length (Lg) of 25 nm. Benefiting from the ultra-thin 7.1 E EOT on HZH films after 450 0C annealing, superior performance, including enhanced driving current (Ion) and short channel effect (SCE) immunity, is achieved on HZH-FinFETs and is maintained with Lg scaled to 25 nm. Compared with traditional HfO2-based FinFETs, a 38% increase in Ion and a 54% improvement in transconductance are observed in HZH-FinFETs with 25 nm Lg. Furthermore, due to the absence of IL scavenging and low interface trap density (Dit) in HZH gate stacks, mobility degradation was not observed in the HZH FinFET. Additionally, the HZH gate stack shows a comparable level of TDDB and NBTI reliability to that of HfO2 devices, indicating the great potential of HZH for future advanced node CMOS technology.