Patent ID: 7655570
Filing Date: 2010-02-02
Classification: H01L

Abstract:
1. An etching method for etching a laminated film having a plurality of layers of silicon-based insulating films formed on a substrate, the silicon-based insulating films including in sequence a first tetraethoxysilane (TEOS) film, a spin-on glass (SOG) film, and a second TEOS film, the etching method comprising: etching the laminated film formed on the substrate by introducing an etching gas into a processing chamber, the etching gas containing a carbon fluoride gas and a nitrogen gas but being essentially devoid of an oxygen gas; and making etching rates of the SOG film and those of the first and second TEOS films substantially identical to each other by setting a ratio of a flow rate of the nitrogen gas to a total flow rate of the etching gas to be about 30%-40%.