Three-dimensional structured memory devices

1. A three-dimensional structured memory device, comprising:

levels of a first conductive material alternating with levels of a first dielectric material such that each level of conductive material is separated from another level of conductive material by a level of dielectric material;

a channel material formed through the alternating levels over sidewalls of the alternating levels;

a second dielectric material formed within the channel material, the second dielectric material having a portion recessed to the channel material on the sidewalls, the channel material proximate to the recessed portion being doped with a dopant of a first polarity and having a diffusion barrier formed thereover; and

a second conductive material formed in the recessed portion and over the diffusion barrier, the second conductive material being doped with a second dopant having a polarity opposite that of the first dopant.

2. The three-dimensional structured memory device of claim 1 , wherein the channel material proximate to the recessed portion is doped with an n-type dopant to form n-type regions.

3. The three-dimensional structured memory device of claim 1 , wherein the second conductive material is doped with a p-type dopant.

4. The three-dimensional structured memory device of claim 1 , wherein the channel material comprises a U-shape formed in adjacent portions of the alternating levels of the first conductive material and the first dielectric material, with a lower connecting-portion of the U-shaped portion formed in a substrate over which such alternating levels are formed.

5. The three-dimensional structured memory device of claim 1 , wherein the second conductive material is polysilicon.

6. The three-dimensional structured memory device of claim 1 , wherein the diffusion barrier is a metal diffusion barrier.

7. The three-dimensional structured memory device of claim 1 , wherein the diffusion barrier is a dielectric diffusion barrier.

8. The three-dimensional structured memory device of claim 1 , wherein the channel material doped with the dopant of the first polarity and the second conductive material doped with the second dopant form a source/drain region.

9. A method, comprising:

forming levels of a first conductive material and levels of a first dielectric material such that each level of conductive material is separated from another level of conductive material by a level of dielectric material;

forming an opening through the levels of the conductive material and levels of dielectric material, the opening having sidewalls;

forming a channel material over the sidewalls within the opening;

forming a second dielectric material over the channel material and at least partially filling the opening;

recessing an uppermost portion of the second dielectric material to expose portions of the channel material;

doping, with a dopant material having a first polarity, exposed portions of the channel material not covered by the second dielectric material;

forming a diffusion barrier over an uppermost portion of the second dielectric material and the doped channel material;

forming a second conductive material in the recessed portion and over the diffusion barrier; and doping the second conductive material with a second dopant having a polarity opposite that of the first dopant.

10. The method of claim 9 , further comprising, prior to forming the second conductive material in the recessed portion and over the diffusion barrier, etching a portion of the diffusion barrier thereby exposing an uppermost portion of the second dielectric material.

11. The method of claim 9 , further comprising, prior to forming the diffusion barrier and forming the second conductive material, further recessing a portion of the second dielectric material thereby exposing additional portions of the channel material.

12. The method of claim 11 , wherein the diffusion barrier is formed to a level below an interface of the channel material and the doped channel material.

13. The method of claim 9 , wherein the diffusion barrier is formed to a level of an interface of the channel material and the doped channel material.

14. The method of claim 9 , further comprising, prior to forming the channel material over the sidewalls:

forming an insulative blocking level adjacent to the sidewalls;

forming a charge storage level over the insulative blocking level; and

forming a insulative tunneling level over the charge storage level.

15. The method of claim 14 , further comprising selecting the insulative blocking level, the charge storage level, and the insulative tunneling level to comprise an oxide-nitride-oxide (ONO) level.

16. A method, comprising:

forming an opening through a device structure;

forming a channel material over sidewalls of the opening;

forming an inter-dielectric material over the channel material;

selectively recessing a portion of the inter--dielectric material to expose a region of the channel material;

doping the exposed region to form an n-type doped region;

forming a diffusion barrier layer over the n-type doped region; and

at least partially filling a remaining portion of the recessed portion with a p-type doped material.

17. The method of claim 16 , further comprising adjusting a concentration of the p-type doped material to be lower than a concentration of an n-type dopant in the n-type doped region.

18. The method of claim 16 , further comprising doping the p-type doped material to include a p+ region and a p− region, wherein a concentration of a p-type dopant is greater in the p+ region than in the p− region.

19. The method of claim 16 , further comprising recessing the inter dielectric prior to forming the diffusion barrier material to expose additional portions of the channel material.

20. The method of claim 19 , wherein forming a diffusion barrier material in the recess further comprises forming the diffusion barrier material over the additional portions of the channel material.