In Reply to: Re: SPUTTER POWER DISTRIBUTION posted by mike plaisted on 12/17/01 at 6:46 AM:
This would be one of the simplier cases. Since the targets are conducting, the sputtering surfaces are all equi-potential (same voltage) so we only have to consider the current flow through each of the tiles. There would be no reason for the current flow to be different if it were not a magnatron configuration. The current flow and hence the power distribution will be slightly lower in the thicker tiles because the magnetic field above those tiles is weaker because the front surface is further from the magnetic poles.
I do not know what your dark space shields look like but if they are closer to the thicker tiles because of the construction there could be an increase in the power distribution through the thick tiles because of the increased electro-static field between the target and the dark space shield. But this increase should be less the the lowering of the power distribution due to the decreased magnetic field.
All of this would manifest itself in a variation of the deposition thickness along long axis of the target. Of couse if your substrates are rotating or orbiting you will not see this. You will see that the thinner tiles erode at a faster rate than the thick ones.
I hope this has been helpful.