Gating tubes applied to three-dimensional flash memory and preparation method thereof

Abstract

The invention belongs to the field of semiconductor storage and particularly discloses gating tubes applied to a three-dimensional flash memory and a preparation method thereof. The gating tubes comprise first metal shielding layers, second metal shielding layers and gating function layers. The gating tubes are disposed at top ends of flash memory strings for forming the three-dimensional flash memory and are directly located above a vertical channel. The gating tubes are in one-to-one correspondence with the flash memory strings, and any of the flash memory strings is vertically set on the substrate in a three-dimensional stacked structure. The gating function layers are used for controlling the gating of the flash memory strings under the gating tubes according to the voltage on or off on the first metal shielding layers and the second metal shielding layers. According to the invention, by improving the internal structures and setting mode of the gating tubes, the problems that the preparation process of the gating tubes is not compatible with the preparation process of the three-dimensional flash memory and the power consumption of the gating tubes is high can be effectively solved compared with the prior art.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional semiconductor memory, and more specifically relates to a gate tube applied to a three-dimensional flash memory and a preparation method thereof. Background technique [0002] According to Moore's Law, the feature size of microelectronic devices continues to decrease, and there is a physical limit to the miniaturization of the special size of flash memory. Therefore, the planar flash memory technology begins to develop into three dimensions, and three-dimensional flash memory emerges as the times require. Compared with the traditional planar semiconductor memory, the storage density of the three-dimensional flash memory is not limited by the feature size of the process, and the storage density can be continuously improved by stacking in the vertical direction. [0003] For three-dimensional flash memories, transistors are usually used to gate a single storage string, and a separate gate t...

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Problems solved by technology

[0005] In view of the above defects or improvement needs of the prior art, the object of the present invention is to provide a gate tube applied to a three-dimensional flash memory and a preparation method thereof, wherein the internal structure and arrangement of the gate tube are improved, and the Compared with the prior art, it can effectively solve the problems that the manufacturing process of the gating tube is incompatible with the manufacturing process of the three-dimensional flash memory, and the power consumption of the gating tube is high. The structure of the gating tube in the present invention is very suitable for the three-dimensional flash memory, and can effectively integrate The internal detailed structure of the three-dimensional flash memory cooperates to realize the gating control of the flash storage string, and the preparation process of the gating tube can be effectively compatible with the existing three-dimensional flash memory manufacturing process, and the two-terminal gating tube is the threshold value of the gating material characteristics to achieve on-state and off-state, while the threshold characteristics of traditional transistors use the gate electrode voltage to deplete or accumulate channel carriers to form off or on, so the present invention can improve the performance of existing three-dimensional flash memory array storage strings Gate speed, simplify process, reduce gate power consumption

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