Three-dimensional storage and formation method therefor

Abstract

The invention discloses a three-dimensional storage and a formation method therefor. The three-dimensional storage comprises a substrate, a plurality of separated stacking layer structures, an isolation layer, a connecting structure and a plurality of inserting plugs, wherein the substrate comprises a device region and a connecting region which are arranged adjacently; the multiple separated stacking layer structures are positioned on the device region and the connecting region of the substrate; the stacking layer structures comprise multiple layers of stacked grids; the isolation layer is positioned on the device region, between adjacent stacking structures, of the substrate; the connecting structure is positioned on the connecting region of the substrate; the connecting structure is connected with the adjacent stacking structures; the connecting structure comprises multiple layers of stacked electric connecting layers; the two ends of each electric connecting layer are connected with the grids on the same layer in the adjacent stacking structures; the multiple inserting plugs are positioned on the surfaces of the grids in each layer; and each inserting plug is electrically connected with the grids in contact, the grids on the same layer with the grids in contact, and the electric connecting layers on the same layer with the grids in contact. By virtue of the formation method, the number of the inserting plugs can be reduced, the process can be simplified, the size of the storage can be reduced, and the space utilization rate of the chip can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a three-dimensional memory and a forming method thereof. Background technique [0002] In recent years, the development of flash memory (flash memory) is particularly rapid. The main feature of flash memory is that it can keep stored information for a long time without power on, and has the advantages of high integration, fast access speed, easy erasing and rewriting, etc. Has been widely used. In order to further increase the bit density of the flash memory while reducing the bit cost, a three-dimensional NAND (3D NAND) flash memory is proposed. [0003] A three-dimensional NAND (3D NAND) flash memory has a plurality of gate layers stacked on a substrate, and a vertical channel runs through the plurality of gate layers. The bottom gate layer is used as a bottom selection transistor, multiple middle gate layers are used as storage transistors, and the top g...

AI Technical Summary

Problems solved by technology

[0004] However, the manufacturing process of the existing three-dimensional NAND gate flash storage unit is complicated and the volume is large, which will reduce the space utilization of the chip

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