Plasma Etching

Plasma Etching

Plasma etching is a process similar to sputter coating - commonly employed for depositing conductive films for SEM inspection. However the process is working in reverse with the specimen forming the cathode in the vacuum reaction cell. High voltage is applied between the anode and cathode which oppose each other with a small gap between. The cathode is the 'target' on which the sample is placed. Gas, usually an inert gas such as argon is leaked under controlled conditions into the vacuum. The gas atoms become positively ionized in the high electrostatic field between the electrodes. The positively charged gas ions accelerate toward the cathode and bombard the sample, eroding the surface in the process. There are many different suppliers and models of plasma etching equipment on the market. Those with low power rating are generally referred to as cleaners, whereas those with higher power or wattage are termed etchers. Plasma etching should generally be used as a means of cleaning or improving a mechanically or electrolytically prepared surface.