Patent ID: 7625494

Claim:
A plasma etching method for etching an organic-material film on a substrate having the organic-material film and an inorganic-material film thereon, said method comprising: an arranging step of arranging first and second electrodes oppositely in a chamber and making the second electrode support the substrate to be processed in such a manner that the substrate is arranged between the first and second electrodes, and an etching step of applying a high-frequency electric power to the second electrode supporting the substrate to form a high-frequency electric field between the first and second electrodes, supplying a process gas into the chamber to form a plasma of the process gas by means of the electric field, and selectively plasma-etching the organic-material film of the substrate by means of the plasma while using the inorganic-material film to function as a mask, wherein said etching step further comprises setting the frequency of the high-frequency electric power applied to the second electrode to 70 to 150 MHz, and controlling a magnetic annular unit having a plurality of rotatable, segment magnets concentrically arranged around the chamber in such a manner that magnetic-pole directions of adjacent two segment magnets are opposite, and that a vertical gap is set between pairs of magnets so as to adjust a magnetic field by the segment magnets to confine the plasma to a region in the chamber, wherein in the etching step, a second high-frequency electric power of 500 kHz to 27 MHz is applied to the second electrode supporting the substrate, the second high-frequency electric power being overlapped with the high-frequency electric power.