Method for forming etching mask and method for manufacturing semiconductor device

A method for forming an etching mask, the method comprising:

• forming a first mask layer containing a first organic material on a layer to be patterned by a subsequent etching;
• forming an intermediate film on the first mask layer;
• forming a second mask layer containing a second organic material on the intermediate film;
• processing the second mask layer to form a pattern including an opening;
• forming a filling layer in the opening;
• impregnating the second mask layer with a metal material in a state in which the filling layer is in the opening;
• removing the filling layer;
• etching the intermediate film and the first mask layer by using the second mask layer;
• and
• removing the intermediate film and the second mask layer, wherein
• the second organic material in the second mask layer includes reaction sites that react with the metal material, and the reaction sites per unit volume of the filling layer is less the reaction sites per the unit volume of the second mask layer.

A method for forming an etching mask, the method comprising:

• forming a mask layer by alternately stacking one or more first organic layers and one or more second organic layers on a layer to be patterned in a subsequent etching;
• processing the mask layer to form a pattern including an opening penetrating the one or more first organic layers and the one or more second organic layers of the mask layer;
• and
• impregnating the mask layer with a metal material, wherein
• the second organic layer includes reaction sites that react with the metal material, and a number of the reaction sites per unit volume in the first organic layer is less than a number of the reaction sites per the unit volume in the second organic layer.