Patent ID: 6423242
Filing Date: 2002-07-23
Classification: C03C,H01J,H01L

Abstract:
An etching method for etching an SiO2 film formed on an SiN film on a substrate with a plasma of a process gas which contains C4F8, said plasma formed by a high-frequency electric field applied between first and second electrodes while introducing the process gas into a chamber held to a reduced pressure with the first and the second electrodes mounted opposite to each other inside the chamber and with the substrate supported by the second electrode, comprising:applying a first high frequency signal in a range from 50 to 150 MHz to the first electrode; applying a second high frequency signal in a range from 1 to 4 MHz to the second electrode and at a power not greater than 800 W; and etching with a pressure of 1.06 to 2.00 Pa.