Experimental Study on Electron Mobility in InxGa1-xAs-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistors With In Content Modulation and MOS Interface Buffer Engineering

In this paper, we study the electron transport properties of thin-body In_xGa_1-xAs-on-insulator (In_xGa_1-xAs-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs) using two types of mobility enhancement engineering: an increase in the Indium (In) content of InGaAs channels and MOS interface buffer engineering. We have demonstrated a high peak mobility of 3180 cm²/(V·s) in our InAs-on-insulator (InAs-OI) MOSFETs, which were fabricated on Si substrates with MOS interface buffer layers by direct wafer bonding. The scattering mechanisms for the electron mobility in In_xGa_1-xAs-OI MOSFETs are systematically analyzed and identified. We conclude that the increase of the In content enhances phonon-limited mobility, whereas the use of the MOS interface buffer enhances thickness-fluctuation-limited mobility through the suppression of thickness fluctuation at the MOS interface.