Broad beam ion source for ion implantation

A broadbeam ion source for ion implantation has been developed. The features of this source include high current density, large beam spot area, and good beam current density uniformity. It can be equipped with a single or multiaperture ion extraction system and can be operated over energy and current ranges of 3–120 keV and 1–60 mA, respectively. Ion beam current densities ranging from 10–500 μA/cm2 and beam spot diameter ranging from 8 to 25 cm are measured at a target location 60 cm downstream from the source. The drift in beam current is less than ±3% with simple unregulated power supply. Many gases, such as nitrogen, argon, hydrogen, oxygen, and other gaseous compounds, can be implanted with this source. A dual-beam dynamic recoil ion mixing system equipped with this kind of source has been built. By using this machine a good mixture between a deposited Mo film and Fe in the Cr4Mo4V steel substrate has been made at near room temperature. Implantation at high dose rates as high as 300 μA/cm2 has been shown to induce deeper penetration than that realized using lower dose rates at the same beam energy.