Methods of forming staircase structures
View Patent ↗Methods of improving adhesion between a photoresist and conductive or insulating structures. The method comprises forming a slot through at least a portion of alternating conductive structures and insulating structures on a substrate. Portions of the conductive structures or of the insulating structures are removed to form recesses in the conductive structures or in the insulating structures. A photoresist is formed over the alternating conductive structures and insulating structures and within the slot. Methods of improving adhesion between a photoresist and a spin-on dielectric material are also disclosed, as well as methods of forming a staircase structure.
1. A method of forming a staircase structure, comprising:
forming a slot through tiers of conductive structures and insulating structures on a material;
selectively forming recesses in the insulating structures;
forming a photoresist over the tiers and within the slot and within the recesses; and
conducting repeated trim acts of the photoresist to form stairs of the staircase structure.
2. The method of claim 1 , wherein forming a slot through tiers of conductive structures and insulating structures comprises forming the slot on an array region of the material.
3. The method of claim 1 , wherein forming a slot through tiers of conductive structures and insulating structures comprises forming the slot on a peripheral region of the material.
4. The method of claim 1 , wherein selectively forming recesses in the insulating structures comprises forming jagged sidewalls in the insulating structures.
5. The method of claim 1 , wherein forming a photoresist over the tiers and within the slot and recesses comprises forming the photoresist at a thickness of from about 1 μm to about 20 μm.
6. The method of claim 1 , further comprising treating surfaces of the insulating structures before forming the photoresist over the tiers.
7. The method of claim 1 , further comprising forming at least one contact structure on the stairs of the staircase structure.
8. The method of claim 1 , further comprising forming a channel material through at least a portion of the tiers of conductive structures and insulating structures.
9. The method of claim 8 , further comprising forming memory cells along a length of the channel material.
10. The method of claim 1 , wherein selectively forming recesses in the insulating structures comprises selectively forming the recesses in the insulating structures without forming the recesses in the conductive structures.
11. The method of claim 1 , wherein forming the slot through tiers of conductive structures and insulating structures comprises forming the slot through polysilicon structures and silicon dioxide structures.
12. The method of claim 1 , wherein forming the slot through tiers of conductive structures and insulating structures comprises forming the slot through tungsten structures and silicon dioxide structures.
13. The method of claim 1 , wherein forming the slot through tiers of conductive structures and insulating structures comprises forming the slot through polysilicon structures and silicon nitride structures.
14. The method of claim 1 , wherein selectively forming recesses in the insulating structures comprises increasing the surface area of the conductive structures.
15. The method of claim 1 , wherein selectively forming recesses in the insulating structures comprises selectively recessing material of the insulating structures adjacent to the slot at from about 30 nm to about 60 nm.
16. The method of claim 1 , wherein selectively forming recesses in the insulating structures comprises selectively removing portions of the insulating structures laterally adjacent the slot.