Abstract
A couple of ion-induced processes are applied to fabricate a highly crystalline film of semiconducting silicide, β-FeSi2 on a Si substrate. One is the sputter deposition process, in which 35 keV Ar+ ions are utilized to deposit sputtered iron (Fe) on Si substrate to form β-FeSi2 in the temperature range around 973 K by means of ion beam sputter deposition (IBSD) method. The other is the sputter etching (SE) of the substrate surface prior to deposition, which plays a critical role in determining the crystalline properties of β-FeSi2 films. Authors have shown that when the SE conditions are properly chosen, continuous and relatively homogeneous β-FeSi2 thin films with high crystal orientation are fabricated with IBSD method in the temperature range of 873-973 K, with the film thickness of 50-100 nm. In addition, the interface is fairly smooth, where the transition layer at the interface is limited to a few atomic layers. Although care was taken to minimize the defect concentration in the obtained films, even the most highly-oriented β-FeSi2 films contain a small amount of defects. To make the defect concentration as low as possible, SE treatment was performed at lower incident energies. It was found that for Ne+ ions the incident energy could be lowered to 0.8 keV to obtain highly-oriented β-FeSi2 films.
