Patent ID: 6902683

Claim:
A method of processing a sample in a plasma processing apparatus comprising a vacuum processing chamber, and a pair of first and second electrodes opposed to each other, wherein the method comprises the steps of: providing the sample, having a diameter of 300 mm or more and including an insulator film, on the first electrode being used also as the sample table, introducing a fluorine-containing etching gas into the environment in which the sample is held; evacuating said environment to a pressure condition of 0.5 Pa to 4.0 Pa; applying a high frequency electric power at 50 MHz to 200 MHz between the first and second electrodes; generating a plasma by a plasma generating means from said etching gas located in an electrode gap between said pair of first and second electrodes, using said pressure condition and said high frequency electric power, thus forming fluoride containing plasma species; providing a plate made of silicon on a bottom surface of the second electrode; setting a gap between the first and the second electrodes to be between 30-60 mm, and plasma processing the sample while decreasing the amount of fluoride species in the gap.