| abstract |
An object of the present invention is to provide an etching method that suppresses the deterioration of the shape of an opening without excessively lowering the productivity. To this end, in the present invention, the step of adhering the support plate 5 to the surface of the semiconductor substrate 1 to cover the pad electrode 3 formed on the semiconductor substrate 1 via the silicon oxide film 2, Forming a via hole 9 to reach the surface of the pad electrode 3 from the back surface of the semiconductor substrate 1, wherein the semiconductor substrate 1 includes at least SF 6 and O 2 . Forming a first opening 7 to a position where the silicon oxide film 2 is not exposed by using an etching gas, and etching comprising at least C 4 F 8 and SF 6 with respect to the semiconductor substrate 1. And forming a second opening 8 to a position where the silicon oxide film 2 is exposed by using a gas.n n n n Semiconductor substrate, silicon oxide film, pad electrode, opening, via hole |