| 摘要 |
A mixed gas containing at least a first fluorocarbon gas having C>=4 and a C/F ratio of 0.625 or higher, a second fluorocarbon gas having F>=4 and a C/F ratio of 0.5 or lower, an Ar gas, and an O2 gas is used as an etching gas to etch an insulating film formed of a silicon oxide film or the like. This can improve an etching rate and a resist mask selection ratio, and in addition, prevent the formation of a contact hole in a bowing shape even when a high-aspect-ratio contact hole is formed. |
