Energy level broadening of defects causing nonideality in nearly ideal Si Schottky barriers

We have proposed a mechanism of the local Schottky barrier height (SBH) lowering to explain the nonideal characteristics in Si SBs. Positively charged defects close to the M/S interface induce image charge in the metal-induced gap states (MIGS) and lower the SBH. Based on this mechanism, the inhomogeneous potential distributions in the proximity of the MIGS are calculated in agreement with the I-V characteristics. The energy level of the defect, identified with Si self-interstitial, is in agreement with the theoretical value. The energy width of the defect is nearly equal to the standard deviation in the Gaussian distribution describing the SBH inhomogeneity. Thus, the propriety of the model is confirmed. (C) 2004 Elsevier B.V. All rights reserved.