| 摘要 |
PURPOSE:To vertically etch a groove having a large aspect ratio at a high speed by disposing a magnetic field generator on a second electrode side opposed to a first electrode for placing a sample, and setting gas pressure to a predetermined value. CONSTITUTION:First and second electrodes 11, 12 are oppositely disposed in a vessel 10. High frequency power is applied from a high frequency power supply 15 through a substrate 13 to be etched to the upper surface of the electrode (cathode) 11 and through a matching circuit 14 to the electrode 11. A magnetic field generator 20 on the upper surface of the electrode 12 forms a predetermined magnetic field between the electrodes 11 and 12 out of the vessel 10, and reciprocates in a direction of an arrow P by a moving mechanism 21. Since a distance between a magnet and a wafer is provided in this system, a high density plasma is formed in a wide range from the vicinity of the anode toward the cathode. When the pressure of the etching gas (Cl2) is 5X10<-3>(Torr) or lower, the etching speed decreases, the etching velocity is decelerated. To effectively vertically etch it without undercut, the gas pressure is preferably 8X10<-3>(Torr) or lower, and may be set to a range of 2-8X10<-3>(Torr).
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