Analysis of I– V measurements on PtSi-Si Schottky structures in a wide temperature range

Abstract

I– V Measurements on PtSi-Si Schottky structures in a wide temperature range from 90 to 350 K were carried out. The contributions of thermionic-emission current and various other current-transport mechanisms were assumed when evaluating the Schottky barrier height Φ 0. Thus the generation-recombination, tunneling and leak currents caused by inhomogeneities and defects at the metal-semiconductor interface were taken into account. Taking the above-mentioned mechanisms and their temperature dependence into consideration in the Schottky diode model, an outstanding agreement between theory and experiment was achieved in a wide temperature range. Excluding the secondary current-transport mechanisms from the total current, a more exact value of the thermionic-emission saturation current I te and thus a more accurate value of Φ b was reached. The barrier height Φ b and the modified Richardson constant A ∗∗ were calculated from the plot of thermionic-emission saturation current I te as a function of temperature too. The proposed method of finding Φ b is independent of the exact values of the metal-semiconductor contact area A and of the modified Richardson constant A ∗∗ . This fact can be used for determination of Φ b in new Schottky structures based on multicomponent semiconductor materials. Using the experimentally evaluated value A ∗∗ = 1.796 × 10 6 Am −2 K −2 for the barrier height determination from I– V characteristics the value of Φ b = 0.881 ± 0.002 eV was reached independent of temperature. The more exact value of barrier height Φ b is a relevant input parameter for Schottky diode computer-aided modeling and simulation, which provided a closer correlation between the experimental and theoretical characteristics.