Aggressively Scaled Strained-Silicon-on-Insulator Undoped-Body High- $kappa$/Metal-Gate nFinFETs for High-Performance Logic Applications

摘要

Strained-silicon-on-insulator (SSOI) undoped-body high-$kappa$ /metal-gate n-channel fin-shaped field-effect transistors (nFinFETs) at scaled gate lengths and pitches (i.e., $L_{rm GATE}sim!!hbox{25 nm}$ and a contacted gate pitch of 130 nm) were fabricated using a gate-first flow. A “long and narrow” fin layout (i.e., fin length $sim!!hbox{1} muhbox{m}$) was leveraged to preserve uniaxial tensile strain in the transistors. These devices exhibit drive currents suitable for high-performance logic technology. The change in the slope of $R_{rm ON} - L_{rm GATE} ({rm dR}_{rm ON}/hbox{dL}_{rm GATE})$, transconductance $G_{rm MSAT}$ , and injection velocity $(v_{rm inj})$ measurements indicate a $sim$15% mobility-induced $I_{rm ON}$ enhancement with SSOI relative to SOI nFinFETs at ultrashort gate lengths. Raman measurements conducted on SSOI substrates after fin formation demonstrate the preservation of $sim$1.3-GPa uniaxial tensile strain even after 1100 $^{circ}hbox{C}$ annealing.