OPTIMIZED MAGNETIC-FIELD SHAPE FOR LOW-PRESSURE MAGNETRON SPUTTERING

Discharge characteristics at low pressures (<0.1 Pa) of an unbalanced magnetron with two electromagnets have been studied. The discharge extinction and ignition pressures are a function of the currents Ixand I2in both electromagnet coils. Minimum pressure is obtained for a particular ratio I2/I1. Extinction pressures range down to 1.5 X10-2Pa. The magnetic field of the magnetron was measured. Its shape was fitted using Bessel functions and the field line pattern solved using Runge-Kutta method. The magnetic field for the minimum extinction and ignition pressures features maximum area of the target covered with the tunnel of magnetic field lines. © 1995, American Vacuum Society. All rights reserved.