Proposal of a new electronic structure model of Ohmic contacts for the future metallic source and drain

Recently, metallic source and drain is widely discussed with LSIs scaling trend. For this technology, it is essential to fabricate low resistive Ohmic contact between electrodes and the channel materials. However, it is expected that precise Schottky barrier height control for obtaining Ohmic contact is technologically difficult. One of the main reasons is that Fermi level pinning phenomena takes place when a metal/semiconductor interface is formed. Recently, we have proposed a new Ohmic contact model in which resonant tunneling through the defect levels in a Schottky barrier is an origin of Ohmic characteristics. In this paper, we have considered our propose Ohmic contact model which is compatible with interface physics concepts, such as a charge neutrality level which can describe essential properties of metal/semiconductor interfaces. We calculate the current-voltage characteristics based on our proposed model up to the operating temperature of the integrated circuits. Our calculated results show that our proposed model can reproduce linear Ohmic I-V characteristics from room temperature to the operation temperature of the integrated circuits.