Etching composition for selectively etching silicon nitride, etching method, and manufacturing method of semiconductor device using the same

1 . An etching composition capable of increasing an etching selectivity for a silicon nitride over a silicon oxide and a polycrystalline silicon, the etching composition comprising:

an inorganic acid;

a solvent; and

an additive,

wherein the additive includes one or both of a compound containing an epoxy group and a compound containing a vinyl group, and the additive is a non-silicon-based additive,

wherein the compound containing the epoxy group includes one or more of allyl glycidyl ether, epichlorohydrin, 1,2-epoxy-3-phenoxypropane, and 2,3-epoxypropyl benzene, and the compound containing the vinyl group includes one or both of vinyl bromide and phenyl vinyl ether, and

wherein the etching composition has an etching selectivity of 50 or more for the silicon nitride compared to the polycrystalline silicon and an etching selectivity of 30 or more for the silicon nitride compared to the silicon oxide.

2 . The etching composition of claim 1 , wherein the inorganic acid is any one selected from the group consisting of phosphoric acid, sulfuric acid, nitric acid, silicic acid, hydrofluoric acid, boric acid, hydrochloric acid, perchloric acid, and a mixture thereof.

3 . The etching composition of claim 2 , wherein the inorganic acid is phosphoric acid.

4 . The etching composition of claim 1 , wherein a content of the inorganic acid in a total amount of the inorganic acid and the solvent is in a range of about 80 to about 90 wt %.

5 . The etching composition of claim 1 , wherein the solvent includes water (H 2 O).

6 . The etching composition of claim 1 , wherein a content of the additive in the etching composition is in a range of about 0.001 to about 20 wt %.

7 . The etching composition of claim 6 , wherein the content of the additive in the etching composition is in a range of about 0.1 to about 3 wt %.

8 . An etching method, comprising:

providing a substrate structure on which a silicon nitride and one or both of a silicon oxide and a polycrystalline silicon are disposed; and

selectively etching the silicon nitride with respect to one or both of the silicon oxide and the polycrystalline silicon by applying the etching composition according to claim 1 to the substrate structure.

9 . The etching method of claim 8 , wherein selectively etching the silicon nitride is performed at a temperature in a range of about 100 to about 200° C.

10 . A manufacturing method of a semiconductor device, comprising:

providing a substrate structure on which a silicon nitride and one or both of a silicon oxide and a polycrystalline silicon are disposed; and

selectively etching the silicon nitride with respect to one or both of the silicon oxide and the polycrystalline silicon by applying the etching composition according to claim 1 to the substrate structure.

11 . The manufacturing method of claim 10 , wherein the semiconductor device is a vertical NAND device.

12 . The manufacturing method of claim 11 , wherein providing the substrate structure comprises:

forming a stacked structure in which a plurality of silicon nitride films and a plurality of silicon oxide films are alternately stacked in a specific direction on a substrate; and

forming a polycrystalline silicon member extending in the specific direction within the stacked structure, and

wherein selectively etching the silicon nitride comprises selectively etching the silicon nitride film with respect to the silicon oxide film and the polycrystalline silicon member by using the etching composition.