| 摘要 |
PURPOSE:To form a dielectric thin-film for a capacitor and an upper electrode without a disconnection at a step, and to improve the yield of an LSI by patterning and forming a resist mask to a contact region coated with thin-films consisting of two layers or more, etching the first thin-film and etching the second thin-film. CONSTITUTION:The surface of an Si substrate 9 to which an impurity is doped in high concentration is oxidized in dried O2 gas to form silicon oxide 10. An Si3N4 film 11 is etched by using an IPC type dry etching device while employing a photo-resist 12 as a mask. After the completion of etching, the film 11 is over- etched after the interference color of the whole surface of a wafer disappears. The whole surface of the Si substrate 9 is exposed by ultraviolet beams, and the resist 12 is fluidized through heat treatment. The silicon oxide is etched for approximately 40sec by an etching liquid at the ratio of hydrogen fluoride water to ammonium fluoride of 1:6. An overhang is not generated between the Si3N4 11 and the silicon oxide 10 by the etching. |
