Considerations on Fermi-depinning, dipoles and oxide tunneling for oxygen-based dielectric insertions in advanced CMOS contacts

International audience; We present experimental and simulated J-V characteristics of Metal/Insulator/Semiconductor (MIS) junctions aiming at improving the contact resistivity for advanced CMOS nodes. We show that an Atomic Layer Deposition (ALD)-based Al2O3 process may induce a native silicon oxide regrowth leading to an additional tunneling resistance in series. A modelling-based analysis of Metal/Insulator/Insulator/Metal (MIIS) contacts, including the potentially beneficial interfacial dipole, provides a new outlook on high-kappa/SiO2 bilayers for low resistivity contacts.