Effect of surface treatment using Cl2 inductively coupled plasma on Schottky characteristics of n-type 4H-SiC

The effect of surface treatment in SiC on the change of Schottky characteristics was interpreted using X-ray photoelectron spectroscopy. The binding energies of both C-Si and Si-C bonds were simultaneously increased about 0.5 eV at the inductively coupled plasma (ICP)-treated surface, meaning that the Fermi level, E-F, shifted toward the conduction bandedge. The increase in the Si/C atomic ratio with the ICP treatment provides evidence that a number of carbon vacancies, V-C, were produced at the treated surface. This supports that E-F pins at the energy level of V-C near the conduction bandedge, leading to the reduction of Schottky barrier height for the transport of electrons as well as independence of Schottky barrier height on the metal work function. (C) 2002 The Electrochemical Society.