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

Semiconducting beta-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 beta-FeSi2 film was formed by depositing an iron layer on the silicon at 600 and 700 degrees C. At lower deposition temperatures, metastable FeSi was present in addition to beta-FeSi2. At 800 degrees C metallic alpha-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 him. However, no significant benefit was obtained. Also, we formed the beta-FeSi2 him by depositing iron on silicon at room temperature and then annealing at 650 degrees C for 120 min. Alternately, iron was deposited at 450 or 550 degrees C, and the beta-FeSi2 film was formed by annealing at 600 degrees C. It was concluded that the best way to produce single phase beta-FeSi2 is to deposit iron at 600 degrees C without any additional heat treatment. The interface between the beta-FeSi2 film and silicon substrate was abrupt. (C) 1999 American Vacuum Society. [S0734-2101(99)05002-2].