Patent ID: 11335573

Abstract:
Disclosed is a dry etching method for etching a metal film on a substrate with an etching gas containing a β-diketone and an additive gas, wherein the metal film contains a metal element capable of forming a complex with the β-diketone; and wherein the amount of water contained in the etching gas is 30 mass ppm or less relative to the amount of the β-diketone. It is preferable that the β-diketone used for the dry etching method is supplied from a β-diketone filled container, wherein the β-diketone filled container has a sealed container body filled with a β-diketone whose water content is 15 mass ppm or less relative to the β-diketone. This etching method enables etching of the metal film while suppressing etching rate variations from the initial stage to the later stage of use of the filled container.