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

Strained-silicon-on-insulator (SSOI) undoped-body high-κ /metal-gate n-channel fin-shaped field-effect transistors (nFinFETs) at scaled gate lengths and pitches (i.e.,
L
_GATE
~ 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 ~ 1 μm) 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
_ON
-
L
_GATE
(dR
_ON
/dL
_GATE
), transconductance
G
_MSAT
, and injection velocity (
v
_inj
) measurements indicate a ~ 15% mobility-induced
I
_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 ~ 1.3-GPa uniaxial tensile strain even after 1100°C annealing.