Ultrathin Body InGaAs-on-Insulator Metal–Oxide–Semiconductor Field-Effect Transistors with InP Passivation Layers on Si Substrates Fabricated by Direct Wafer Bonding

We demonstrated the formation of ultrathin-body (UTB) III–V-semiconductor-on-insulator (III–V-OI) n-channel metal–oxide–semiconductor field-effect transistors (nMOSFETs) on Si by low-damage direct wafer bonding, where channel thickness was been reduced to 7 nm. However, we found a significant reduction of the effective mobility of the InGaAs-OI nMOSFETs upon thinning InGaAs channels without surface passivation layers. Instead, we demonstrated the high electron mobility of 1004 cm 2 ·V -1 ·s -1 in a 9-nm-thick InGaAs-OI nMOSFET with an InP surface passivation layer. This finding indicates that the proper surface passivation is important in realizing the high-performance UTB III–V-OI nMOSFETs.