Electron and hole components of tunneling currents through an interfacial oxide-high-k gate stack in metal-oxide-semiconductor capacitors

摘要

Two different components of tunneling current in the TiN/HfSiO_xN/SiO_2/p-Si(100) metal-oxide-semiconductor capacitor have been presented. The tunneling currents were calculated by taking into account a longitudinal-transverse kinetic energy coupling. The calculated tunneling currents were compared with that measured ones by employing the electron and hole effective masses and phase velocities as fitting parameters. It has been shown that hole tunneling currents dominate at low voltages whereas at high voltages the tunneling currents are mainly contributed by electrons. It has also been found that the effective mass of hole in the HfSiO_xN layer is higher than that of electron. The gate electron and substrate hole velocities are 1 × 10~5 m/s independent of the HfSiO_xN thickness. In addition, it is speculated that the electron and hole effective masses in the HfSiO_xN layer perhaps increase as its thickness decreases.