Method of planarizing the surface of a semiconductor device, in which silicon nitride is used as isolating material

摘要

A method of planarizing the surface of a semiconductor device comprising a substrate carrying on its surface a contact configuration, which method essentially consists in that the following steps are successively carried out: (a) depositing a silicon nitride layer, (b) depositing a lacquer layer, whose free surface is substantially flat, (c) progressively attacking by plasma the lacquer layer until the farthest projecting parts of the silicon nitride layer are completely exposed, the complete appearance of these farthest projecting parts being detected by recording the intensity variations of an emitted jet of nitrogen, (d) attacking simultaneously by plasma the silicon nitride layer and the remaining lacquer until the contact configuration completely appears. This method is characterized in that the conditions of attack are chosen so that the rate of attack of the lacquer is higher than the rate of attack of the silicon nitride in order to detect with increased sensitivity the complete appearance of the contact configuration.