Achieving Low V-T (<-0.3v) And Thin Eot (Similar To 1.0nm) In Gate First Metal/High-K Pmosfet For High Performance For High Performance Cmos Applications

A metal/high-k gate stack with P-type band edge effective work function (EWF) of 5.1 similar to 5.2 eV is achieved through optimization of a Ru-Al based metal electrode. The critical factors controlling the high EWF values are found to be Al incorporation at the high-k/SiO2 interface and stabilization of the conductive RuO2 layer at the electrode/high-k interface. A pMOSFET with a fully optimized RuAl metal electrode system demonstrates a long channel V-t of -0.29 V with EOT= 1.05nm.