Rf. Schmitsdorf et al., CORRELATION BETWEEN BARRIER HEIGHT AND INTERFACE STRUCTURE OF AG SI(111) SCHOTTKY DIODES/, Surface science, 324(2-3), 1995, pp. 249-256
Barrier heights of Ag/n-Si(111)-''7 x 7'' and -1 x 1 Schottky contacts
were determined from their current-voltage and capacitance-voltage ch
aracteristics. The zero-bias barrier heights were found to decrease pr
oportional to the ideality factor. For ideal diodes with image-force-c
ontrolled ideality factors n(if) = 1.01, zero-bias barrier heights of
0.70 and 0.74 eV were obtained with Ag/n-Si(111)-''7 x 7'' and -1 x 1
diodes, respectively. The lower barrier heights of ''7 x 7''-reconstru
cted with respect to unreconstructed 1 x 1 interfaces are explained by
the stacking fault in one of the triangular subunits of the ''7 x 7''
unit mesh. Stacking faults in bulk silicon are electrically neutral b
ut are associated with electric dipoles. In ''7 x 7''-reconstructed me
tal/Si(111) contacts the fault-induced dipoles are oriented such that
the respective barrier heights are lower than at unfaulted 1 x 1 inter
faces.