Open AccessThe work experimentally determines the changes of magnetic field in the magnetron sputtering system discharge because of electron Hall current near the cathode surface with different magnetic fields. The Hall current was also measured.
The magnetic field changes caused by Hall current were determined as a difference of the magnetic field induction values, which was measured with and without electric discharge. The magnet probe measured magnetic field induction changes. This probe had thermal stabilization and was electrically disconnected from plasma volume to eliminate the influence of temperature on its sensitivity. Magnetic field was placed normal to the magnet lines.
The Hall current value was determined by its simulation with a test coil placed near the cathode surface in the zone of maximum cathode erosion. This test coil caused equivalent changes of the magnetic field. The plasma density has a maximum value in the area of maximum cathode erosion with the highest magnetic field, which is parallel to the cathode. This assumption allows us to suggest that almost entire Hall current is concentrated in this area. Then, it is possible to replace Hall current effect of magnet field changes for the current in the test coil placed over the cathode surface in the maximum erosion area. The current in the test coil is equal to the total Hall current when this magnetic field change corresponds to the change with discharge available.
The experiment has shown that the magnetic field changes caused by Hall current in DC magnetron sputtering system does not exceed 3% of the external magnetic field value. The Hall current value in magnetron sputtering system with disk-like cathode 4 - 6 times exceeds discharge current. The small value of the Hall current may be explained by the fact that in the cathode area with the maximum plasma concentration and large values of the magnetic field, the current transport is carried out by ions on which the magnetic field does not have significant influence.
The data obtained in this experiment allow us to ignore the changes of magnetic field caused by the Hall current in the theoretical analysis of the plasma parameters in the discharge gap of the magnetron sputtering system.