SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PURPOSE:To provide a semiconductor device having a thin film structure with an etching selectivity ratio and its manufacturing method. CONSTITUTION:A semiconductor device has a structure where a silicon oxide film 2 containing no fluorine and a silicon oxide film 3 containing fluorine are by turns laminated on a substrate or a film structure having a silicon oxide film having different fluorine concentration in the film thickness direction. Etching is automatically stops by obtaining a selectivity ratio required for forming a wiring groove 4 while using different etching speed of the silicon oxide film according to the difference in concentration of fluorine. A characteristic of the silicon oxide film does not change largely so that a film structure of good quality equally to a silicon oxide film not containing impurities can be obtained. Further, since a specific dielectric constant drops by containing fluorine, speed up of the device becomes possible.