A New Direction for III–V FETs for Mobile CPU Operation Including Burst-Mode: In0.35Ga0.65As Channel

In this letter, we show that conventional III–V MOSFETs with moderate/high In content channels (In
_0.53
Ga
_0.47
As or In
_0.70
Ga
_0.30
As) at scaled nodes are incompatible with mobile SoC designs, which often operate at intermediate/high
${V_{{\mathrm {dd}}}}$
(0.7 V to
$\geq 1$
V) to achieve high frequency including during burst-mode. The incompatibility is due to conventional III–V FETs having too small bandgap, and thus too high leakage when operated at the increased voltages. We show that FETs with a more optimal lower In content, In
_0.35
Ga
_0.65
As, have the necessary combination of larger bandgap (~Si) and sufficiently high injection velocity (~2.5 times Si) to enable both low leakage and high performance (versus Si), across the entire
${V_{{\mathrm {dd}}}}$
range of mobile SoC operation. We report for the first time the growth and characterization of ultra-thin In
_0.35
Ga
_0.65
As FETs with a standard 1nm EOT gate dielectric. Calibrated models show that In
_0.35
Ga
_0.65
As enables the highest performance at very low leakages at intermediate/high
${V_{{\mathrm {dd}}}}$
in short channel FETs.