PREPARATION AND EVALUATION OF NiGe GATE ELECTRODES FOR METAL-OXIDE-SEMICONDUCTOR DEVICES

摘要

Next-generation metal-oxide-semiconductor (MOS) devices will require metal gate electrodes to eliminate some problems which conventional poly-Si gate electrodes have, such as gate depletion, high resistivity, chemical reaction with high-k dielectrics and so on. In this study, we have investigated the characteristics of NiGe gate electrodes for MOS devices. An interface between NiGe and gate SiO_2 films was highly stable after post-deposition annealing at high temperature. The work function of the NiGe was found to depend on the annealing temperature and obtained to be ranging from 4.79 eV to 4.94 eV, which stands by the valence band side. The sheet resistance was an order of magnitude lower than that of the conventional poly-Si gate. Because of these features, NiGe is a promising candidate for PMOS device.