Method of dry etching

Abstract

A dry etching method for dry etching a silicon oxide film or a multilayer oxide film thereof which enables formation of contact window to good dimensional precision and with stable etching configuration in the process of film etching at submicron level. A compound gas containing a C element or S element or Cl element, and F element (e.g., CF.sub.4) is used as a principal gas, and a compound gas containing a C element and two or more of H elements (e.g., CH.sub.2 F.sub.2) as an additive gas is used, in the process of dry etching silicon oxide film or a multilayer film thereof. By using principal and additive gases having good step coverage of deposit produced by plasma reaction, it is possible to eliminate any etching residue and form contact windows having stable etching configuration and good dimensional accuracy in the process of film etching at submicron level. By using a compound gas containing a greater number of H element atoms than C element atoms, the deposit on the etching side wall can be a soluble one having a low F element content, such as (C.sub.x H.sub.y)n polymer, and can be readily removed through after-etching washing.

Dependencies are inferred from the claim text.