Etching gas composition and method of manufacturing integrated circuit device using the same

An etching gas composition comprising:

• an organic fluorine compound including aliphatic hydrocarbon having 3 to 10 carbon atoms, in which at least one of hydrogen atoms bonded to carbon is replaced with a fluorine atom;
• carbon disulfide;
• an inert gas;
• and
• a reactive gas.

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

• alternately stacking a plurality of insulating layers and a plurality of sacrificial layers one by one on a substrate;
• forming a stepped structure by removing one end of each of the plurality of insulating layers and the plurality of sacrificial layers;
• forming an insulating block covering the stepped structure;
• replacing the plurality of sacrificial layers with a plurality of gate stacks;
• forming an insulating layer on the insulating block;
• forming an etching mask on the insulating layer;
• forming a contact hole by etching the insulating block and the insulating layer through the etching mask by using plasma obtained from an etching gas composition;
• and
• removing the etching mask, wherein the etching gas composition includes:
• an organic fluorine compound;
• and carbon disulfide.