Method of manufacturing sacrificial layer and method of manufacturing semiconductor device by using the same

A method of manufacturing a semiconductor device, the method comprising:

• providing a first compound and a second compound on a substrate having a plurality of conductive structures formed thereon, the first compound comprising an amine compound including at least one secondary amine, and the second compound including an isocyanate compound;
• forming a sacrificial layer comprising polyurea between the plurality of conductive structures through a polymerization reaction of the first compound and the second compound;
• forming a capping layer covering upper surfaces of the plurality of conductive structures and an upper surface of the sacrificial layer;
• and
• forming an air gap between the plurality of conductive structures by heating the substrate, on which the capping layer is formed, to thermally decompose the sacrificial layer.

A method of manufacturing a semiconductor device, the method comprising:

• providing a first compound represented by Formula 1 and a second compound represented by Formula 2 on a substrate on which a plurality of conductive structures and a hard mask layer covering upper surfaces of the plurality of conductive structures are formed;
• forming a sacrificial layer comprising polyurea between the plurality of conductive structures through a polymerization reaction of the first compound and the second compound;
• recessing an upper portion of the sacrificial layer by using the hard mask layer as an etch mask;
• forming a capping layer covering the upper surfaces of the plurality of conductive structures and an upper surface of the sacrificial layer;
• and
• thermally decomposing the sacrificial layer by heating the substrate on which the capping layer is formed, wherein
• in the forming the sacrificial layer, the substrate is maintained at a temperature of 50° C. to 150° C., and
• in the thermally decomposing the sacrificial layer, the substrate is maintained at a temperature of 200° C. to 400° C.,
• wherein, in each of Formulae 1 and 2,
• A1 and A3 are each independently a C1-C7 alkylene group,
• A2 is a single bond or a C1-C7 alkylene group,
• X is O, S, or N—R,
• R is a C1-C7 alkyl group,
• R1 and R2 are each independently a C2-C7 alkyl group,
• R3 and R4 are each independently hydrogen or a C1-C7 alkyl group, and
• n is an integer from 0 to 3.