Microscopic Understanding of Schottky Barrier Height at Epitaxial-Al/(111)Si Interface

We have measured Schottky barrier heights (SBHs) at epitaxial-Al/n-Si(111) interfaces by three independent methods. In the as-deposited state, the discrepancy among the measured SBHs is attributed to the crystalline defects introduced in the near-surface region of Si during e-gun evaporation. Although this discrepancy among the “macroscopic” values of SBH is reduced upon annealing at 400°C, electrical inhomogeneity is observed in a microscopic scale by means of scanning internal-photoemission microscopy.