AVS 46th International Symposium
    Thin Films Division Tuesday Sessions
       Session TF-TuA

Paper TF-TuA1
Preparation of Co and CoN@sub x@ Thin Films by Unbalanced r.f. Magnetron Sputtering

Tuesday, October 26, 1999, 2:00 pm, Room 615

Session: Fundamentals of Si and Dielectric PVD
Presenter: T. Tanaka, Hiroshima Institute of Technology, Japan
Authors: T. Tanaka, Hiroshima Institute of Technology, Japan
A. Kitabatake, Sanyo Shinku Kogyo, Japan
K. Kawabata, Hiroshima Institute of Technology, Japan
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It has been difficult to deposit ferromagnetic thin films by using a conventional planar magnetron sputtering at low pressure. We have developed a modified process based on an unbalanced magnetron sputtering of a magnetic Co target (100 mm, 5mm thick) to deposit Co and CoN@sub x@ films where an external magnet is added to a conventional planar magnetron to confine the efficient plasma near the magnetron target. The plasma confinement can be controlled by the shape of the magnetic field in the sputter deposition device with a multipolar magnetic-field plasma confinement. Cobalt films were prepared by this sputtering system at the r.f. powers of 100 to 200 W and argon pressure less than 5x10@super -3@ Torr. It is shown that the deposition rate of Co films significantly increases from 8.7 to 25 nm/min whose values are two times that of a conventional magnetron sputtering. Co film with the preferred orientation of (111) plane is formed and the value of the grain size estimated from the plane is about 30 nm. Cobalt nitride (CoN@sub x@) films were also prepared by the unbalanced magnetron sputtering in mixtured argon and nitrogen plasma. It is also found from the results of electron probe microanalysis that the content of nitrogen in CoN@sub x@ films increases with the increasing gas flow ratio of N@sub 2@ . The electrical resistivity for reactively sputtered films is less than 80x10@super -6@ @ohm@ cm which makes this compound a relatively good conductor.