I/O device optimization techniques tailored for highly-scaled FinFET technology

Performance and reliability of I/O FinFET device were co-optimized by fin surface smoothing and LDD Si interstitialization with the aim at the scalability. The fin surface smoothing process demonstrated Ion-Vt performance improvement by +6% / +3% for I/O N/PMOS, along with +8% speed gain in I/O ring oscillators. And core devices leveraged the merit, exhibiting +2% Ion-Ioff benefit with comparable electrostatics and variability. For I/O NMOS drain design, LDD Si interstitialization implantation achieved Isub reduction and 2.5× hot-carrier lifetime improvement, thanks to the well-engineered enhanced diffusion.