Fabricating three-dimensional semiconductor structures

A method, comprising:

• forming, on a substrate, a layer stack of alternating first layers of a first carbon-containing material and second layers of a second carbon-containing material, the first layers and the second layers deposited by spin-on deposition, the first layers comprising:
• a photoresist material or a developable anti-reflective coating;
• and
• a thermal acid generator (TAG);
• executing a first bake of the substrate, the first bake causing the TAG to generate acid in the first layers, the acid modifying the first layers to be soluble in a developer;
• etching first openings through the layer stack;
• filling the first openings with a first fill material that comprises a metal oxide material;
• etching second openings through the layer stack;
• exposing the first layers to the developer to remove the first layers from the layer stack;
• replacing the first layers with a third material, the third material being an oxide or a nitride;
• removing the second layers from the layer stack;
• replacing the second layers with a fourth material;
• removing the first fill material from the first openings;
• and
• replacing the first fill material in the first openings with a second fill material that comprises one or more of silicon dioxide, silicon nitride, and polysilicon.

A method for fabricating a three-dimensional (3D) NAND device, comprising:

• forming, on a substrate, a layer stack of alternating first layers of a first carbon-containing material and second layers of a second carbon-containing material, the first layers and the second layers deposited by spin-on deposition, the first layers comprising:
• a photoresist material or a developable anti-reflective coating;
• and
• an agent-generating ingredient for generating a solubility-changing agent in response to an activation trigger;
• executing the activation trigger, the solubility-changing agent being generated from the agent-generating ingredient in the first layers in response to the activation trigger, the solubility-changing agent modifying the first layers to be soluble in a developer;
• etching channel holes through the layer stack;
• filling the channel holes with a third material;
• etching slits through the layer stack, the slits exposing the alternating first layers and second layers of the layer stack;
• removing the first layers from the layer stack by exposing the first layers to the developer;
• replacing the first layers with a fourth material, the fourth material being an insulating material, the insulating material comprising an oxide or a nitride;
• removing the second layers from the layer stack by exposing the second layers to an etch chemistry;
• and
• replacing the second layers with a fifth material, the fifth material being a metal-containing material.