Temperature analysis of the Gaussian distribution modeling the barrier height inhomogeneity in the Tungsten/4H-SiC Schottky diode

摘要

The temperature dependence of the electrical properties of the Schottky barrier contact W/4H-SiC is studied in term of the Werner's model assuming a Gaussian distribution of the barrier height to model the inhomogeneity of the Schottky interface. The Gaussian distribution is characterized by the parameters Φ_B as a mean barrier height, ρ_2,ρ_3 as coefficients quantifying the barrier deformation and σ_s as a standard deviation. The effect of the series resistance R_s and its relation with the standard deviation σ_s is also reported. A vertical optimization process is used to extract simultaneously all the parameters cited above as function of temperature from the forward current-voltage (Ⅰ-Ⅴ) characteristics at temperatures ranging from 303 to 448 K. The temperature dependence of the characterized parameters of the W/4H-SiC Schottky structure enables us to quantify the inhomogeneity state of the Schottky barrier height prevailing at the MS interface in terms of those extracted parameters.