Method of processing a substrate and a device manufactured by using the method

A method of processing a substrate, the method comprising:

• stacking a stacked structure including an insulation layer and a first sacrificial layer a plurality of number of times;
• etching the stacked structure to form a stepped structure on the stacked structure;
• forming a second sacrificial layer on the first sacrificial layer;
• forming a third sacrificial layer on the second sacrificial layer;
• densifying the third sacrificial layer;
• etching at least a portion of a sacrificial word line structure including the first sacrificial layer, the second sacrificial layer, and the third sacrificial layer;
• forming an interlayer insulation layer on the sacrificial word line structure;
• removing the sacrificial word line structure;
• and
• forming a conductive word line structure corresponding to the sacrificial word line structure.

A method of processing a substrate, the method comprising:

• forming a first silicon nitride layer on a stepped structure having an upper surface, a lower surface, and a side surface that connects the upper surface to the lower surface;
• forming a second silicon nitride layer on the first silicon nitride layer;
• selectively densifying the second silicon nitride layer;
• and
• performing a wet etching process on the first silicon nitride layer and the second silicon nitride layer,
• wherein, during the wet etching process, an etch rate of a portion of a nitride layer on the side surface is greater than an etch rate of portions of a nitride layer on the upper and lower surfaces.

A method of processing a substrate, the method comprising:

• forming at least one layer on a stepped structure having an upper surface, a lower surface, and a side surface that connects the upper surface to the lower surface;
• selectively densifying, via asymmetric plasma application, portions of the at least one layer respectively on the upper surface and the lower surface except for the side surface;
• and
• performing an isotropic etching process on the at least one layer,
• wherein, during the isotropic etching process, the portion of the at least one layer formed on the upper surface is separated from the portion of the at least one layer formed on the lower surface.