High performance and reliable strained SiGe PMOS FinFETs enabled by advanced gate stack engineering
Strained-SiGe, with high-Ge-content, has recently drawn significant attention as an alternate p-channel option for advance FinFETs. Among various technological challenges, gate stack is so critical to enable high-performance FETs. In this paper, key process details of the optimized gate stacks in high-Ge SiGe, such as IL formation and passivation, are disclosed and feasibility of Vth tuning by an ultra-thin replacement metal-gate scheme down to 15nm LG is demonstrated, for the first time. Moreover, near ideal SS, excellent reliability and mobility at scaled EOTs are achieved, which has led to high transconductance devices with proper junction engineering. In addition, we demonstrate the most aggressively-scaled SiGe fins reported to date formed by 3D-Ge-condensation, exhibiting excellent short-channel characteristics.