Formation of β-FeSi2 films by pulsed laser deposition using iron target

Abstract

Semiconducting β-FeSi2 films were formed by pulsed laser deposition on silicon (100) substrates. The phase and crystallinity were examined by x-ray diffraction spectrometry. In the simplest scheme a single phase β-FeSi2 film was formed by depositing an iron layer on the silicon at 600 and 700 °C. At lower deposition temperatures, metastable FeSi was present in addition to β-FeSi2. At 800 °C metallic α-FeSi2 was mixed into the film. We used a laser target made of iron and silicon in addition to the iron target to form a multilayer of thin iron and silicon films. However, no significant benefit was obtained. Also, we formed the β-FeSi2 film by depositing iron on silicon at room temperature and then annealing at 650 °C for 120 min. Alternately, iron was deposited at 450 or 550 °C, and the β-FeSi2 film was formed by annealing at 600 °C. It was concluded that the best way to produce single phase β-FeSi2 is to deposit iron at 600 °C without any additional heat treatment. The interface between the β-FeSi2 film and silicon substrate was abrupt.