Low pressure radio frequency and microwave discharges for d.c. sputtering of ferromagnetic materials

This paper describes a d.c. diode sputtering system in which the sputtering discharge is sustained by an r.f. or microwave plasma excited with a helix coil surrounded by eight SmCo magnets. The discharge is characterized in t erms of the discharge d.c. current through the cathode. The microwave and r .f. excitation and two different configurations of the magnets are compared . The production of r.f. or microwave discharge in a magnetic field makes i t possible to operate this system even at low pressures down to 0.01 Pa.