Integrated assemblies having transistor body regions coupled to carrier-sink-structures; and methods of forming integrated assemblies
Some embodiments include an integrated assembly having a carrier-sink-structure, and having digit lines over the carrier-sink-structure. Transistor body regions are over the digit lines. Extensions extend from the carrier-sink-structure to the transistor body regions. The extensions are configured to drain excess carriers from the transistor body regions. Lower source/drain regions are between the transistor body regions and the digit lines, and are coupled with the digit lines. Upper source/drain regions are over the transistor body regions, and are coupled with storage elements. Gates are adjacent the transistor body regions. The transistor body regions, lower source/drain regions and upper source/drain regions are together comprised a plurality of transistors. The transistors and the storage elements are together comprised by a plurality of memory cells of a memory array. Some embodiments include methods of forming integrated assemblies.
1. A method of forming an integrated assembly, comprising:
forming a stack comprising, in ascending order, a first semiconductor material, an insulative material, a digit line material, and a second semiconductor material; the first semiconductor material being either p-type doped or n-type doped, and the second semiconductor material being the other of p-type doped and n-type doped;
patterning the insulative material, the digit line material, and the second semiconductor material into rails extending along a first direction; the rails being spaced from one another by gaps; regions of the first semiconductor material being exposed along bottom peripheries of the gaps; the rails having sidewalls along the gaps; the patterned digit line material within the rails being digit lines;
forming first insulative spacers along the sidewalls of the rails;
forming semiconductor extensions along the first insulative spacers; the semiconductor extensions and the first insulative spacers narrowing the gaps;
forming second insulative spacers within the narrowed gaps;
forming a planarized surface extending across the rails, the first insulative spacers, the semiconductor extensions and the second insulative spacers;
forming third semiconductor material over and directly against the planarized surface;
forming slits extending through the third semiconductor material to the second insulative spacers; the slits extending linearly along the first direction;
forming insulative panels within the slits;
forming trenches extending through the third semiconductor material and the insulative panels; the trenches extending along a second direction which crosses the first direction; the trenches patterning the third semiconductor material into pillars comprising transistor body regions; the second semiconductor material comprising first source/drain regions under the transistor body regions;
forming gate dielectric material along sidewalls of the transistor body regions;
forming wordlines along the gate dielectric material; the wordlines extending along the second direction;
forming second source/drain regions within upper regions of the pillars;
forming storage elements coupled with the second source/drain regions;
wherein the first source/drain regions, the second source/drain regions and the transistor body regions are together incorporated into access transistors;
wherein the access transistors and the storage elements are incorporated into memory cells of a memory array; and
wherein the semiconductor extensions are configured to drain excess carriers from the transistor body regions to the first semiconductor material during operation of the memory cells.
2. The method of claim 1 wherein the storage elements are capacitors.
3. The method of claim 1 wherein the gate dielectric material consists of silicon dioxide.
4. The method of claim 1 wherein the insulative material, the first insulative spacers, the second insulative spacers and the insulative panels are all a same composition as one another.
5. The method of claim 4 wherein the insulative material, the first insulative spacers, the second insulative spacers and the insulative panels all comprise silicon dioxide.
6. The method of claim 1 wherein at least one of the insulative material, the first insulative spacers, the second insulative spacers and the insulative panels is a different composition relative to another of the insulative material, the first insulative spacers, the second insulative spacers and the insulative panels.
7. The method of claim 1 wherein the first, second and third semiconductor materials are a same composition as one another.
8. The method of claim 7 wherein the first, second and third semiconductor materials comprise silicon.
9. The method of claim 1 wherein at least one of the first, second and third semiconductor materials is a different composition from at least one other of the first, second and third semiconductor materials.