Advanced composite high-κ gate stack for mixed anion arsenide-antimonide quantum well transistors

This paper demonstrates the integration of a composite high-κ gate stack (3.3 nm Al
₂
O
₃
-1.0 nm GaSb) with a mixed anion InAs
_0.8
Sb
_0.2
quantum-well field effect transistor (QWFET). The composite gate stack achieves; (i) EOT of 4.2 nm with <;10
^-7
A/cm
²
gate leakage (ii) low D
_it
interface (~1×10
¹²
/cm
²
/eV) (iii) high drift μ of 3,900-5,060 cm
²
/V-s at N
_S
of 5×10
¹¹
-3×10
¹²
/cm
²
. The InAs
_0.8
Sb
_0.2
MOS-QWFETs with composite gate stack exhibit extrinsic (intrinsic) g
_m
of 334 (502) μS/μm and drive current of 380 μA/μm at V
_DS
= 0.5V for Lg=1μm.