Integrated assemblies having conductive posts extending through stacks of alternating materials
Some embodiments include an integrated assembly having a conductive expanse over conductive nodes. The conductive nodes include a first composition. A bottom surface of the conductive expanse includes a second composition which is different composition than the first composition. A stack is over the conductive expanse. The stack includes alternating first and second levels. Pillar structures extend vertically through the stack. Each of the pillar structures includes a post of conductive material laterally surrounded by an insulative liner. At least one of the posts extends through the conductive expanse to directly contact one of the conductive nodes. Some embodiments include methods of forming integrated assemblies.
1 . An integrated assembly, comprising:
a conductive expanse over conductive nodes comprising a first composition,
wherein a bottom surface of the conductive expanse comprises a second composition which is different composition than the first composition;
wherein the bottom surface of the conductive expanse is at an elevation above a base that is greater than or equal to an elevation above the base of an uppermost surface of the conductive nodes;
a stack over the conductive expanse, wherein the stack comprises alternating first and second levels, a memory array region, a staircase region adjacent to the memory array region, and a peripheral region adjacent to the memory array region,
wherein the first levels comprise silicon nitride;
wherein a first set of the conductive nodes is under the memory array region;
openings extending vertically through the stack with each of the openings lined with a respective insulative material liner, the respective insulative material liner being in direct physical contact with a respective post of conductive material;
pillar structures extending vertically through the openings, wherein:
each of the pillar structures comprises the respective post of conductive material laterally surrounded by the respective insulative material liner;
the conductive material comprises the first composition; and
the respective post extending through the conductive expanse and partially penetrating into a respective conductive node of the conductive nodes, wherein the respective post directly contacts the respective conductive node; and
conductive wordline material formed within voids of the first levels, wherein the voids are formed by removing the silicon nitride of the first levels.
2 . The integrated assembly of claim 1 , wherein the first levels are NAND wordline levels, and wherein the second levels are insulative levels.
3 . The integrated assembly of claim 2 , wherein the NAND wordline levels include metal, and wherein the insulative levels include silicon dioxide.
4 . The integrated assembly of claim 1 , wherein:
the conductive expanse and the stack are within a first tier; and
at least one of the conductive nodes is coupled with circuitry of a second tier under the first tier.
5 . The integrated assembly of claim 4 , wherein the circuitry of the second tier includes CMOS circuitry.
6 . The integrated assembly of claim 1 , wherein a first set of the pillar structures extends through the memory array region, a second set of the pillar structures extends through the peripheral region, and a third set of the pillar structures extends through the staircase region.
7 . The integrated assembly of claim 6 , wherein the memory array region includes at least two decks of memory levels stacked one atop another.
8 . The integrated assembly of claim 6 , wherein the posts from the first set of the pillar structures, the posts from the second set of the pillar structures, and the posts from the third set of the pillar structures are among the posts extending through the conductive expanse.
9 . The integrated assembly of claim 6 , wherein only the posts from the first and second sets of the pillar structures are among the posts extending through the conductive expanse.
10 . The integrated assembly of claim 1 , further comprising collars surrounding regions of the posts that extend through the conductive expanse, wherein the regions are immediately below the bottom surface of the conductive expanse.
11 . The integrated assembly of claim 10 , wherein the collars comprise a third composition which is different from the first composition and the second composition.
12 . The integrated assembly of claim 11 , wherein:
the first composition consists essentially of tungsten;
the second composition comprises tungsten silicide; and
the third composition comprises at least one of metal silicide, metal carbide and metal nitride.
13 . The integrated assembly of claim 12 , wherein the third composition comprises titanium nitride.