Material and Device Characteristics of Metamorphic ${rm In}_{0.53}{rm Ga}_{0.47}{rm As}$ MOSHEMTs Grown on GaAs and Si Substrates by MOCVD

摘要

We report a comparison of material and device characteristics of metamorphic ${rm In}_{0.53}{rm Ga}_{0.47}{rm As}$ channel metal–oxide–semiconductor high-electron mobility transistors (MOSHEMTs) grown on GaAs and Si substrates by metal–organic chemical vapor deposition. A gate-last process was developed to simplify the fabrication of nanoscale channel length devices. Selective source/drain regrowth was incorporated to reduce parasitic resistances. Post-metallization annealing (PMA) was utilized to mitigate the weakened gate electrostatic control in the buried channel. The effect of PMA on the ${rm Ti}/{rm Al}_{2}{rm O}_{3}$ gate-stack was investigated in detail. Record-low ON-state resistance of 132 and 129 $Omegacdotmu{rm m}$ has been achieved in enhancement-mode InGaAs MOSHEMT on GaAs and on Si substrate, respectively. A 120-nm channel length device on GaAs exhibited a figure of merit $Q({rm g}_{m}/{rm SS})$ of 12, whereas a 60-nm channel length ${rm In}_{0.53}{rm Ga}_{0.47}{rm As}$ MOSHEMT on Si demonstrated $Q$ up to 14.