Plasma PH3-passivated high mobility inversion InGaAs MOSFET fabricated with self-aligned gate-first process and HfO2/TaN gate stack

Abstract

N-type InGaAs MOS devices are fabricated using HfO2/TaN and HfAlO/TaN gate stacks. Both direct deposition and novel in-situ plasma PH 3 surface passivation are compared. The PH3-passivated MOS capacitances shows high performance with EOT=1.7∼3.0 nm, J g=2x10-5 A/cm2 at Vg=2 V. After RTA, gate stack maintains stable with excellent C-V frequency dispersion of 1.3%. Silicon implanted InGaAs achieves good n+-p rectifying characteristic and low resistivity in the n+ S/D by 600 °C RTA. Inversion-mode nMOSFET exhibits remarkable enhancement with the PH3-passivation. It shows an excellent S.S.=96 mV/dec and μeff=1600 cm2/Vs. There is significant reduction in S.S. and leap in drain current comparing to the recent reported inversion-mode III-V MOSFET and unpassivated control samples. In addition, sub 100 nm InGaAs MOSFET with the self-aligned gate-first process is demonstrated for the first time.