The current-voltage-temperature characteristics of PtSi/p-Si Schottky barrier diodes were measured in the temperature range 60-115 K. Deviation of the ideality factor from unity below 80 K may be modelled using the so-called T0 parameter with T0 = 18 K. It is also shown that the curvature in the Richardson plots may be remedied by using the flatband rather than the zero-bias saturation current density. Physically, the departure from ideality is interpreted in terms of an inhomogeneous Schottky contact. Here we determine a mean barrier height at T = 0 K, Φ̄0 b = 223 mV, with an (assumed) Gaussian distribution of standard deviation σΦ, = 12.5 mV. These data are correlated with the zero-bias barrier height, Φ0 j = 192 mV (at T = 90 K), the photoresponse barrier height, Φph = 205 mV, and the flatband barrier height, Φfb = 214 mV. Finally, the temperature coefficient of the flatband barrier was found to be -0.121 mV K-1, which is approximately equal to 1/2(dEi g/dT), thus suggesting that the Fermi level at the interface is pinned to the middle of the band gap.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry