Evidence for the double distribution of barrier heights in Schottky diodes fromI-V-Tmeasurements

Abstract

The current-voltage (I -V ) characteristics of palladium silicide-based Schottky diodes on n-type silicon have been measured over a wide temperature range (66-300 K). Their analysis on the basis of the thermionic emission-diffusion (TED) mechanism reveals an abnormal decrease of zero-bias barrier height and increase of ideality factor with decrease in temperature (T ) and nonlinearity in the activation energy plot. Such behaviour is attributed to barrier inhomogeneities by assuming a Gaussian distribution of barrier heights at the silicide/silicon interface. Evidence is given for the existence of a double Gaussian distribution having mean barrier heights of 0.79 V and 0.64 V and standard deviations of 0.081 V and 0.057 V with ideality factors 1.064 and 1.363, and remain effective in the temperature range 134-300 K and 66-120 K respectively. Further, the effect of forward bias on the distribution parameters is discussed. A simple method, involving the use of a zero-bias barrier height versus inverse temperature plot, is suggested to deduce the presence of single/multiple distribution(s) of barrier heights and to determine the respective parameters.

Interface state density analyzing of Au/TiO2(rutile)/n–Si Schottky barrier diode

“…In addition, when the interfacial layer is sufficiently thick and the transmission probability between the metal and the N ss is very small, the effective barrier height, φ e , is assumed to be bias dependent due to presence of an interfacial insulator layer and N ss located between interfacial layer and semiconductor interface, and is given by [16] …”

Temperature Dependent Current-Voltage and Capacitance-Voltage Characteristics of an Au/n-Type Si Schottky Barrier Diode Modified Using a PEDOT:PSS Interlayer

“…20) The N D and ) B (C-V) for the Au/ PEDOT:PSS/n-Si SBD can be calculated from eq. (10) Table 1, the donor concentration of the n-Si slightly increases as the temperature increases.…”

Double Gaussian Distribution of Barrier Heights, Interface States, and Current Transport Mechanisms in Au/Bi0.5Na0.5TiO3-BaTiO3/n-GaN MIS Structure

“…39 The temperature dependence of r o is usually small and can be neglected. 40 According to Eq. 10, a plot of U ap versus 1/2kT should be a straight line with the intercept at the ordinate estimating the zero-bias mean value of SBH (U bo ) and the slope giving the zero-bias standard deviation (r o ).…”

“…The intercepts and slopes of these straight lines give two sets of values of U bo and r o as 1.91 eV and 0.215 eV in the temperature range from 210 K to 420 K (distribution 1), and 1.07 eV and 0.118 eV in the temperature range from 120 K to 210 K (distribution 2). Moreover, Chand and Kumar 40 indicated the existence of a double Gaussian distribution in metal-semiconductor contacts which could be attributed to the nature of the inhomogeneities themselves, which may involve variation in the interface phase composition, interface quality, electrical charges, nonstoichiometry, etc. These are important enough to electrically control the I-V characteristics of the Schottky diodes, particularly at low temperatures.…”