Dual Strained Channel CMOS in FDSOI Architecture: New Insights on the Device Performance

We report an original Dual Strained Channel On Insulator (DSCOI) Fully Depleted CMOS architecture by co-integrating nFETs on sSOI and pFETs on Si/c-SiGe/(s)SOI with a TiN/HfO2 gate stack (EOT=1.15nm) and down to 40nm gate lengths. We demonstrate for the first time large gains for transconductance (up to +125%) and mobility (+100%) even for short channel pFETs. This enables us to improve the ON(OFF) pFETs trade-off (ION+23% for a given IOFF=100nA/μm), and thus to obtain similar ION for n and pFETs (∼650μA/μm at VDD=1V). Meanwhile, thanks to a channel material/strain engineering, the threshold voltages are adjusted (Vth∼±0.2V) for high performance (HP) CMOS with a single mid-gap metal gate. Extracted interface trap densities (NT=5–8.5×1017cm−3eV−1) using low frequency noise indicate the excellent integrity of the TiN/HfO2 stack when compared to SOI reference samples.