Three-dimensional flash memory device
Provided are various three-dimensional flash memory devices. A three-dimensional flash memory device includes a gate stacked structure, separate arc-shaped channel pillars, source/drain pillars and a charge storage structure. The gate stacked structure is disposed on a substrate and includes a plurality of gate layers electrically insulated from each other. The arc-shaped channel pillar are disposed on the substrate and located in the gate stacked structure. The source/drain pillars are disposed on the substrate and penetrate through the gate stacked structure, wherein two source/drain pillars are disposed at two ends of each of the arc-shaped channel pillars. The charge storage structure is disposed between each of the plurality of gate layers and the corresponding arc-shaped channel pillar.
1. A three-dimensional flash memory device, comprising:
a gate stacked structure, disposed on a substrate and comprising a plurality of gate electrode layers insulated from each other;
a plurality of separate arc-shaped channel pillars, disposed on the substrate and located in the gate stacked structure;
a plurality of source/drain pillars, disposed on the substrate and penetrating through the gate stacked structure, wherein each of the plurality of arc-shaped channel pillars has two source/drain pillars disposed at two ends thereof; and
a charge storage structure, disposed between each of the plurality of gate electrode layers and the corresponding arc-shaped channel pillar,
wherein each arc-shaped channel pillar comprises two end surfaces separate from each other, and two source/drain pillars are correspondingly connected to the end surfaces of each of the arc-shaped channel pillars.
2. The three-dimensional flash memory device of claim 1 , wherein two adjacent arc-shaped channel pillars are in a mirror symmetrical configuration.
3. The three-dimensional flash memory device of claim 1 , wherein two adjacent arc-shaped channel pillars are in a non-mirror symmetrical configuration.
4. The three-dimensional flash memory device of claim 1 , wherein an insulating pillar is disposed between two adjacent arc-shaped channel pillars.
5. The three-dimensional flash memory device of claim 4 , wherein two adjacent insulating pillars are aligned in a row direction perpendicular to a direction that two adjacent channel pillars of the plurality of separate arc-shaped channel pillars are face-to-face, and the insulating pillars of different rows are in a staggered arrangement.
6. The three-dimensional flash memory device of claim 4 , wherein two adjacent insulating pillars are aligned in a row direction perpendicular to a direction that two adjacent channel pillars of the plurality of separate arc-shaped channel pillars are face-to-face, and the insulating pillar of different rows are in an aligned arrangement.
7. The three-dimensional flash memory device of claim 1 , wherein the source/drain pillars at the corresponding ends of two adjacent arc-shaped channel pillars are separated from each other.
8. The three-dimensional flash memory device of claim 7 , wherein a contact plug is electrically connected to the source/drain pillars at the corresponding ends of the two adjacent arc-shaped channel pillars.
9. The three-dimensional flash memory device of claim 8 , wherein the contact plug is electrically connected to a conductive wire over the gate stacked structure.
10. The three-dimensional flash memory device of claim 9 , wherein the conductive wire comprises a source line or a bit line.
11. The three-dimensional flash memory device of claim 1 , wherein the source/drain pillars at the corresponding ends of two adjacent arc-shaped channel pillars in a mirror symmetrical configuration are connected to each other.
12. The three-dimensional flash memory device of claim 11 , wherein a contact plug is electrically connected to the connected source/drain pillars.
13. The three-dimensional flash memory device of claim 1 , wherein a sidewall of each of the charge storage structures has a substantially smooth profile.
14. The three-dimensional flash memory device of claim 1 , wherein a sidewall of each of the charge storage structures has a wavy profile.
15. The three-dimensional flash memory device of claim 1 , wherein each of the plurality of arc-shaped channel pillars is continuous in an extension direction thereof.
16. The three-dimensional flash memory device of claim 1 , wherein each of the plurality of arc-shaped channel pillars is discontinuous in an extension direction thereof, and channel portions of the arc-shaped channel pillar merely correspond to the gate electrode layers.
17. The three-dimensional flash memory device of claim 1 , wherein distances from two ends of each of the plurality of arc-shaped channel pillars to the corresponding gate electrode layer are constant.
18. The three-dimensional flash memory device of claim 1 , wherein distances from two ends of each of the plurality of arc-shaped channel pillars to the corresponding gate electrode layer are non-constant.
19. The three-dimensional flash memory device of claim 1 , wherein the plurality of arc-shaped channel pillars comprises undoped polysilicon, and the plurality of source/drain pillars comprises doped polysilicon.
20. The three-dimensional flash memory device of claim 1 , wherein from a top view, each of the plurality of source/drain pillars is an L-shape, an I-shape, an irregular shape, a polygonal shape, an arc shape, an annular shape or a combination thereof.