Etchant composition for etching silicon germanium film and method of manufacturing integrated circuit device by using the same

A method of manufacturing an integrated circuit device, the method comprising:

• forming, on a substrate, a mold layer in which a plurality of silicon films and a plurality of silicon germanium films are alternately stacked;
• forming an insulating structure to cover a sidewall of the mold layer;
• forming a mold pattern by forming a trench through anisotropic etching of the plurality of silicon films and the plurality of silicon germanium films, the mold pattern including respective remaining portions of the plurality of silicon films and the plurality of silicon germanium films, which define the trench;
• and
• forming a plurality of air gaps by selectively removing, from the mold pattern, the plurality of silicon germanium films through the trench by using an etchant composition, the plurality of air gaps exposing the plurality of silicon films and the insulating structure,
• wherein the etchant composition includes:
• about 5 wt % to about 14 wt % of an oxidant, based on a total weight of the etchant composition;
• about 0.01 wt % to about 5 wt % of a fluorine compound, based on the total weight of the etchant composition;
• about 0.01 wt % to about 5 wt % of an amine compound, based on the total weight of the etchant composition;
• about 0.01 wt % to about 1 wt % of an alcohol compound having a hydrophilic head and a hydrophobic tail, based on the total weight of the etchant composition;
• about 60 wt % to about 90 wt % of an organic solvent, based on the total weight of the etchant composition;
• and
• a balance of water.