LATERAL VARIATION IN THE SCHOTTKY-BARRIER HEIGHT OF AU/PTSI/(100)SI DIODES

The lateral variation in the Schottky barrier height (SBH) formed at UHV prepared Au/PtSi/(100)Si (n = 4.5 x 10(14)) diodes was measured on length scales ranging from a few to several hundred nanometers using ballistic electron emission microscopy (BEEM). The spatial profile and the statistical distribution of the SBHs thus obtained were compared to broad area current-voltage (I-V) and capacitance-voltage (C-V) characteristics of these metal-semiconductor contacts. This comparison showed that the macroscopic SBHs obtained from I-V and C-V measurements can be successfully interpreted using the parallel conduction model applied to the BEEM derived barrier height distribution. In addition, we found that the variations in the SBH were strongly correlated, with an autocovariance length of approximately 20 nm at short wavelengths and with a strong peak in the spectral density at a spatial frequency of approximately (225 nm)-1.