Characterization of electrical and crystallographic properties of metal layers at deca-nanometer scale using Kelvin probe force microscope

As device dimensions are scaled down, the variations of electrical and chemical properties within metal electrodes have a critical impact on MOSFETs and Metal/Insulator/Metal (MIM) capacitors characteristics. In this letter, we report on Work Function (WF) measurements performed at deca-nanometer scale using Kelvin probe Force Microscope (KFM). We first demonstrated the relationship between the WF value and the grain crystallographic orientation by combining KFM and Electron Back Scattered Diffraction (EBSD) performed over the same Cu area. Once this relationship was established, KFM was used to provide, in addition to the WF value, the crystallographic properties of PVD TiN films grown on various substrates. Finally we measured an increase of 0.26 eV of the WF of TiN grown by CVD after N2/H2 plasma treatment. In the latter case, the modification of the bulk chemical potential by post-treatment has been proposed.