BARRIER CHARACTERISTICS OF PTSI P-SI SCHOTTKY DIODES AS DETERMINED FROM I-V-T MEASUREMENTS/

The current-voltage-temperature characteristics of PtSi/p-Si Schottky barrier diodes were measured in the temperature range 60-115 K. Deviat ion of the ideality factor from unity below 80 K may be modelled using the so-called T-0 parameter with T-0 = 18 K. It is also shown that th e curvature in the Richardson plots may be remedied by using the flatb and rather than the zero-bias saturation current density. Physically, the departure from ideality is interpreted in terms of an inhomogeneou s Schottky contact. Here we determine a mean barrier height at T = 0 K , phi(b)(-0) = 223 mV, with an (assumed) Gaussian distribution of stan dard deviation sigma(phi) = 12.5 mV. These data are correlated with th e zero-bias barrier height, phi(j)(0) = 192 mV (at T = 90 K), the phot oresponse barrier height, phi(ph) = 205 mV, and the flatband barrier h eight, phi(fb) = 214 mV. Finally, the temperature coefficient of the f latband barrier was found to be -0.121 mV K-1, which is approximately equal to 1/2(dE(g)(i)/dT), thus suggesting that the Fermi level at the interface is pinned to the middle of the band gap.