MOSFETs with high mobility channel materials and higher-k/metal gate stack

Integration of lanthanum lutetium oxide (LaLuO 3 ) with a к value of 30 is demonstrated on high mobility biaxially tensile strained Si (sSi) and compressively strained SiGe for fully depleted n/p-MOSFETs as a gate dielectric. N-MOSFETs on sSi fabricated with a full replacement gate process indicated very good electrical performance with steep subthreshold slopes of ∼72 mV/dec and I on /I off ratios up to 109. Strained SOI (sSOI) channel devices show higher electron mobility of 385 cm2/Vs compared to the reference device on SOI which has a mobility of 188 cm2/Vs. P-MOSFETs fabricated on sSi/Si 0.5 Ge 0.5 /sSOI heterostructure with a gate first process showed a subthreshold swing of 92 mV/dec and an I on /I off ratio of 105. The extracted hole mobilities are similar to the reference device with HfO 2 as gate dielectric, and are much higher than the hole mobilities in Si.