Patent ID: 8084358
Filing Date: 2011-12-27
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising the steps of: (a) forming a first conductive film on a substrate; (b) forming an insulating film on the first conductive film; (c) forming on the insulating film a mask film having an opening exposing the insulating film; (d) anisotropically etching the insulating film exposed to the opening to form a recess in an upper part of the insulating film exposed to the opening and to cause a reaction product of a material of the insulating film and a material of an etching gas used for the anisotropic etching to adhere to a lower part of a sidewall portion of the mask film in the opening; (e) performing isotropic etching by using the reaction product as a mask to decrease the sidewall portion of the mask film in the opening in a horizontal direction to a main surface of the substrate, and performing anisotropic etching to etch the insulating film exposed at a bottom of the recess in a vertical direction to the main surface of the substrate while removing the reaction product adhering to the lower part of the sidewall portion of the mask film in the opening; (f) after the step (e), performing anisotropic etching by using the remaining mask film as a mask, thereby etching the insulating film present around the recess in the vertical direction to the main surface of the substrate to form a stepped portion in the insulating film, and also etching the insulating film exposed at the bottom of the recess to expose the first conductive film; and (g) after removing the remaining mask film, forming a second conductive film on the first conductive film exposed to the recess and on the insulating film.