Electron transport of inhomogeneous α-FeSi 2/(111)Si Schottky barriers

Abstract

Continuous buried layers of metallic α-FeSi 2 were fabricated by Ion Beam Synthesis in (111)Si substrates. Laterally patterned α-FeSi 2 Schottky diodes with different areas were fabricated by implantation through an SiO 2 mask. While diode characteristics were only observed on n-type Si, on p-type Si nearly ohmic behaviour was observed. The analysis of I– V curves indicated a strong temperature dependence; in the high temperature range between 360 and 420 K, the contacts showed nearly ideal behaviour with ideality factors n ⩽ 1.1 and an exceptionally high Schottky barrier height of Φ B = 0.96 ± 0.02 eV. At lower temperatures we observed non-ideal behaviour of the electron transport through the α-FeSi 2/(111)Si interfaces, revealed by ideality factors larger than 1 and a bias-dependence of the effective Schottky barrier height Φ eff. All effects can be attributed to Schottky barrier inhomogeneities.