Method for manufacturing semiconductor device

摘要

First through fourth wiring layers are formed on the surface of a silicon substrate, then a silicon oxide layer containing fluorine is deposited over the wiring layers and the silicon substrate, and then another silicon oxide layer containing no fluorine is deposited over the silicon oxide layer containing fluorine. Subsequently, the silicon oxide layer containing no fluorine is flattened by polishing it for a predetermined length of time when the silicon oxide layer containing no fluorine is polished, the silicon oxide layer containing fluorine serves as a stopper, since the polishing rate of the silicon oxide layer containing fluorine is lower than that of the silicon oxide layer containing no fluorine.