Etchant composition and method of fabricating semiconductor device

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

• forming, on a substrate, a structure in which a plurality of silicon oxide layers and a plurality of silicon nitride layers are alternately stacked one by one;
• forming a cut region by partially removing each of the plurality of silicon oxide layers and the plurality of silicon nitride layers, the cut region having a sidewall at which the plurality of silicon oxide layers and the plurality of silicon nitride layers are exposed;
• and
• selectively removing the plurality of silicon nitride layers out of the plurality of silicon oxide layers and the plurality of silicon nitride layers through the cut region by bringing an etchant composition for silicon nitride into contact with the structure,
• wherein the etchant composition for silicon nitride includes:
• an inorganic acid aqueous solution,
• about 0.01 parts by weight to about 0.5 parts by weight of colloidal silica having an average particle size of about 1 nm to about 40 nm;
• about 0.01 parts by weight to about 30 parts by weight of an ammonium-based additive;
• and
• about 20 parts by weight to about 50 parts by weight of a solvent,
• all parts by weight being based on 100 parts by weight of the inorganic acid aqueous solution,
• wherein the colloidal silica is dissolved in the inorganic acid and has a structure represented by Chemical Formula 1:
• wherein, in Chemical Formula 1,
• m is an integer of 2 to 8, and
• R1, R2, R3, R4, R5, R6, R7, and R8 are each independently a hydrogen atom, a hydroxyl group, or a group represented by Chemical Formula 2, at least one of R1, R2, R3, R4, R5, R6, R7, and R8 being a hydroxyl group or a group represented by Chemical Formula 2,
• wherein, in Chemical Formula 2,
• n is an integer of 0 to 5, and
• R9 and R10 are each independently a hydrogen atom, a hydroxyl group, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C1 to C20 hydroxyalkyl group, a C1 to C20 aminoalkyl group, a C1 to C20 alkoxy group, a C1 to C20 aminoalkoxy group, a nitrile group, or a carboxyl group.

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

• forming a structure in which a plurality of silicon oxide layers and a plurality of silicon nitride layers are alternately stacked one by one on a substrate in a deposition chamber;
• forming a cut region by partially removing each of the plurality of silicon oxide layers and the plurality of silicon nitride layers in a dry etching chamber such that the cut region has a sidewall at which the plurality of silicon oxide layers and the plurality of silicon nitride layers are exposed;
• and
• selectively removing the plurality of silicon nitride layers out of the plurality of silicon oxide layers and the plurality of silicon nitride layers through the cut region by bringing an etchant composition for silicon nitride into contact with the structure in a wet etching chamber,
• wherein:
• the etchant composition for silicon nitride includes a phosphoric acid solution including colloidal silica and an ammonium-based additive,
• selectively removing the plurality of silicon nitride layers is performed at a temperature of about 200° C. to about 300° C.,
• the colloidal silica dissolved in the inorganic acid has a structure represented by Chemical Formula 1:
• in Chemical Formula 1,
• m is an integer of 2 to 8, and
• R1, R2, R3, R4, R5, R6, R7, and R8 are each independently a hydrogen atom, a hydroxyl group, or a group represented by Chemical Formula 2, at least one of R1, R2, R3, R4, R5, R6, R7, and R8 being a hydroxyl group or a group represented by Chemical Formula 2,
• in Chemical Formula 2,
• n is an integer of 0 to 5, and
• R9 and R10 are each independently a hydrogen atom, a hydroxyl group, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C1 to C20 hydroxyalkyl group, a C1 to C20 aminoalkyl group, a C1 to C20 alkoxy group, a C1 to C20 aminoalkoxy group, a nitrile group, or a carboxyl group.