Improvement of the Electrical Properties of β-FeSi 2 Films on Si (001) by High-Temperature Annealing

Abstract
The crystal quality, mobility and carrier density of the continuous and [100]-oriented nondoped β-FeSi2 films prepared from Si/Fe multilayers on Si (001) substrates using templates were improved by high-temperature annealing, in particular, at 900°C. All the annealed samples exhibited n-type conduction. The maximum electron mobility of β-FeSi2 indicated 6900 cm2/V·s (46 K) after annealing at 900°C for 42 h. This mobility is about 15 times higher than that reported so far for nondoped n-type β-FeSi2. The electron density at room temperature decreased from 2×1020 cm-3 to 3×1018 cm-3 after the annealing.