Magnetic field distribution and I-V characteristics of newly-developed magnetron sputtering cathode

A novel type of magnetron sputtering cathode was developed. The magnetic field distributions and strengths in front of the target can be precisely adjusted by controlling separately the currents of the three-coil electromagnets of the newly-developed cathode. The impact of the magnetic field distribution on the current-voltage characteristics was experimentally studied. The results show that the field distribution significantly affects the discharge stability and the plasma density distribution. For example, a converged magnetic field traps the secondary electrons in a narrow region near the target, lowers the ion flux close to the substrate, but improves the uniformity of the radial distribution of the plasma. A judicious choice of the excitation currents may considerably improve the magnetron sputtering.