What is DC plasma and how is it different from AC plasma?

[maharshi_qis]

DC plasma...

what is meant by DC plasma.....how is different from AC plasma.

 

[CK815]

Re: DC plasma...

The difference between AC and DC plasma is the way they are generated. DC plasma relies on the fact that a gas held between two electrodes which have a potential high enough will be ionized. The effect is called DC glow discharge. Electrons will be accelerated towards the anode, ions towards the cathode. If a conductive material is placed on the cathode, accelerated ions will bombard the material and lead to a process called sputtering. If an insulator is placed between the electrodes, the plasma will not be able to form under DC conditions (think of a capacitor!). Here, AC is required (usually in the RF range 10MHz - 14MHz). This is the process used for plasma etching of wafers.

Regards,

C.