Magnesium plasma immersion ion implantation on silicon wafers

Magnesium ions were implanted by plasma immersion ion implantation on Si wafers. The vacuum arc plasma gun has a straight configuration, and samples were biased from −2 to −8 kV with 20-μs pulses at 700 Hz, with or without a magnetic field of 150 G, with arc currents of 600 A. Three samples were positioned 85 cm away from the anode grid, one sample with its surface facing the plasma stream and perpendicular to B (frontal samples), while the others have surfaces parallel to the plasma stream and the magnetic field (lateral samples). High-resolution X-ray diffraction results showed that implantation occurred, as evidenced by distortion of the rocking curves obtained. Deposition with thickness of the order of 1 μm also occurred, but was considerably thinner for samples positioned parallel to the plasma stream. Lateral samples are also free of macroparticles, as shown by SEM observations. The presence of a magnetic field significantly increases the implanted current and the deposition thickness in frontal samples, since plasma density is increased by two orders of magnitude.