Important research targets to be explored for β-FeSi2 device making

We have performed high-dose iron (Fe) ion implantation into a single crystalline silicon (Si) substrate in order to synthesize a β-FeSi2∕Si heterostructure. Si(001) substrates were implanted with 120keV Fe ions at 623K to a fluence of 4×1017∕cm2, followed by thermal annealing at temperatures ranging from 773to1073K. Implantation-induced microstructures as well as annealing-induced ones were examined by means of x-ray diffraction (XRD) and transmission electron microscopy (TEM) in combination with energy-dispersive x-ray spectroscopy. Grazing-incidence XRD and cross-sectional TEM observations indicated that a continuous iron silicide layer consisting of e-FeSi and β-FeSi2 is formed in as-implanted samples. With increasing annealing temperature the e-FeSi phase transformed into the β-FeSi2 one, and finally a continuous β-FeSi2 polycrystalline layer was formed on the topmost layer of the Si substrate. Pole figure XRD measurements revealed that the β-FeSi2 crystallites are not randomly oriented but possess a ...

Formation process of β-FeSi2∕Si heterostructure in high-dose Fe ion implanted Si

The effect of Mn and Al dopants on the β-FeSi2 stabilization by a two-step route: Mechanical alloying and annealing

Carbon-doped β–FeSi2 films synthesized by ion implantation are investigated with the aim to fabricate high-quality semiconducting β–FeSi2 layer on silicon substrate. According to transmission electron microscopy (TEM) cross-section observations, carbon-doped films with homogeneous thickness and smooth β–Si interface, have higher quality than binary Fe–Si films. In particular, annealing at 500°C–700°C leads to the formation of a flat and continuous β-type silicide layer. Improved stability of the β phase is also found. Optical emission spectroscopy measurements show that the carbon doping influences only slightly the band gap values.

T. Takada

Papers

Fabrication of heterostructure p-β-Fe0.95Mn0.05Si2/n-Si diodes by Fe+ and Mn+ co-implantation in Si(100) substrates