chamber this embodiment will be explained by referring to fig1 the third electrode uses a surface treated sic 112 which is supplied by a power 119 to etch the sic with a plasma the sic 112 is temperature regulated by a heater 116 and a cooling pipe 117 other elements are similar to those of the embodiment 12 with the etching rate of the pyrolytic graphite plate of the upper electrode 1202 varied from 100 nm min to 400 nm min the sic 112 wall supplied by the power 119 to measure changes in the etching rate of the resist silicon oxide film silicon film and silicon nitride film on the wafer according to the etching rate of the sic wall electrode it was found that as the etching rate of the sic electrode increased the etching rate of the oxide film changed from 500 nm min to 1500 nm min and the etching rate of the resist film changed from 300 nm min to 60 nm min in other words the etching rate of the resist was able to be adjusted by the etching rate of the sic wall electrode to keep the selectivity high the etching rate of the silicon film also changed in the similar manner to that of the resist it is also found that to realize the most selective etching of the silicon nitride film requires increasing the etching rate of the sic wall electrode this embodiment has demonstrated that the silicon oxide film can be etched at a high etching rate with a plasma of gas not containing carbon by including carbon in the solid surface in contact with the plasma and by causing an.