hi pat, good to hear from you.thanks for answering my question.let me be more clear this time.firstly the pressure that i mentioned is for the high vacuum gauge(ion gauge), it is not the high vacuum precision gauge.this pressure falls when the filament is turned on,for me it starts of with 10(-4) and goes down till 10(-6) and even to 10(-7) at times.this happens only when the filament is turned on.under high vacuum condition, i mean when the system is under high vacuum,the pressure displayed on the high vacuum precision gauge is 0 mtorr.again when start pumping in gas into the chamber(argon gas) through the gas inlet(pumped in after closing the throttle valve) the pressure in the precision gauge increases and this i am maintaining at 3.5 to 5 mtorr and the gas is at 15 to 17 slpm.
i don't know if the pressure in the high vacuum gauge effects the current to the chamber,but i do know that the gas flow rate will effect the voltage supplied.for very little gas flow there will be more voltage and vice versa.
as this is a 4 target operated machine, we have different materials on the targets, i am trying to use all the targets to deposit the material.we have aluminium, copper and nickel.
i would like to request you if you could be more clear about the electrode grounding that you mentioned in the last para graph of your note.do you mean target (material to be deposited) when you said sputtering electrode?
i would also like to know if it is fine with you if i can call you up and talk to you over the phone.
if you feel it is ok with you, could you send your land line number to this address:firstname.lastname@example.org