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

We report a comparison of material and device characteristics of metamorphic In_0.53Ga_0.47As 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 Ti/Al₂O₃ gate-stack was investigated in detail. Record-low ON-state resistance of 132 and 129 Ω·μm 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(g_m/SS) of 12, whereas a 60-nm channel length In_0.53Ga_0.47As MOSHEMT on Si demonstrated Q up to 14.