Fabricating three-dimensional semiconductor structures

A method, comprising:

• forming, on a substrate, a layer stack comprising alternating layers of a first spin-on material and a second spin-on material, each layer of the first spin-on material of the layer stack and the second spin-on material of the layer stack formed by spin-on deposition;
• etching first openings through the layer stack;
• filling the first openings with a first fill material;
• etching second openings through the layer stack;
• removing the first spin-on material from the layer stack;
• replacing the first spin-on material with a fourth material, the fourth material being an oxide or a nitride;
• removing the fill material from the first openings;
• replacing the fill material with a fifth material;
• removing the second spin-on material from the layer stack;
• and
• replacing the second spin-on material with a sixth material.

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

• forming, on a substrate, a layer stack of alternating layers of a first spin-on material and a second spin-on material, each layer of the first spin-on material and the second spin-on material formed by spin-on deposition;
• 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 layers of the layer stack;
• removing the first spin-on material from the layer stack by exposing the layers of the first spin-on material to a first etch chemistry;
• replacing the first spin-on material with a fourth material, the fourth material being an insulating material, the insulating material comprising an oxide or a nitride;
• removing the second spin-on material from the layer stack by exposing the layers of the second spin-on material to a second etch chemistry;
• and
• replacing the second spin-on material with a fifth material, the fifth material being a metal-containing material.