Elimination of droplets using a vane velocity filter for pulsed laser ablation of FeSi2

Semiconducting β-FeSi2 is a future promising material for Si-ULSI compatible optoelectronics devices, solar cells and IR photo-sensors. Pulsed laser deposition (PLD) make possible low temperature growth of β-FeSi2. However many droplets are co-deposited with the ablation species, and thus the films obtained by PLD are difficult to be applied for electronic devices. In order to eliminate droplets, a vane velocity filter was adapted. The droplets decreased drastically. The velocity distribution was obtained for various droplet sizes. The maximum velocity of droplets is at most 65 m/s. It is possible to eliminate the droplets completely at the suitable cutoff velocity of the filter.