Ti+ and Mg+ Ion Beam Extraction from the Modified Bernas Ion Source

The korea multi-purpose accelerator complex (KOMAC) has a metal-ion-beam irradiation facility (150 keV/1 mA) equipped with a Bernas ion source. Metal-ion beams such as Cr + , Fe + , Co + , and Cu + have been successfully extracted from our facility. Recently, some research groups have requested us to irradiate Ti + and Mg + ions into materials. These two kinds of ions have never been provided before. In response to these requests, we carried out the extraction of Ti + and Mg + beams at our facility. The vaporization temperatures of TiCl(III) and MgCl(II) under a pressure of 10 −4 Torr were less than 300 °C and more than 600 °C, respectively. In this study, optimal extraction conditions for Ti + and Mg + ion beams were acquired successfully. To confirm the fluences of the Ti + and the Mg + beams, we prepared a silicon wafer sample and a gallium nitride (GaN) sample. Ti + ions were irradiated with a current density of ∼6 μA/cm 2 onto a silicon wafer sample for 90 min, and the dose was 1.68 × 10 16 ions/cm 2 , we measured by using Rutherford backscattering spectrometry (RBS) analysis. Mg + ions implanted in GaN were confirmed by using secondary ion mass spectroscopy (SIMS). The depth and the concentration of Mg + ions at the peak were found to be 130 nm and 7.4 × 10 19 ions/cm 3 , respectively. We would expect the newly extracted Ti + and Mg + ions to be helpful for research in the fields of material science and condensed matter physics.