Memory device and method of manufacturing the same

Abstract

The present application discloses a storage device and a manufacturing method thereof. The manufacturing method includes: sequentially forming a stack layer, a second sacrificial layer, and a first hard mask layer on the surface of a substrate, and the stack layer includes a plurality of alternately stacked first sacrificial layers. and a plurality of interlayer insulating layers or alternately stacking a plurality of gates and a plurality of interlayer insulating layers; forming a patterned first hard mask layer; forming a plurality of via holes penetrating through the stacked layers and reaching the substrate; And removing the second sacrificial layer and the patterned first hard mask layer, the first hard mask layer is a boron-doped amorphous carbon material layer. By using a boron-doped amorphous carbon material layer (Sophia) as the first hard mask layer, the pattern can be transferred to the stack layer through a thinner mask layer. During the photolithography process, the photolithography machine The station can compensate the overlay alignment accuracy at the current station, and then complete the photolithography with higher precision and also solve the problem of further compression of the photolithography window in the photolithography etching process.

Description

technical field [0001] The present invention relates to the field of manufacturing storage devices, and more particularly, to a storage device and a manufacturing method thereof. Background technique [0002] As storage devices in semiconductor devices are widely used in daily life, people pay more and more attention to highly integrated electronic devices, and high-speed, low-power, high-density semiconductor storage devices are rapidly developed. 3D NAND device is an emerging flash memory developed by the industry. It solves the limitations brought by 2D NAND devices or planar NAND devices by vertically stacking multi-layer data storage units. It has higher precision and effectively reduces manufacturing costs. and energy consumption. Due to the increasing number of stacked layers of storage devices, the manufacture of important structural vias (Channel Holes) in the storage core area of ​​3D NAND devices requires higher process precision and greater aspect ratios. [00...

AI Technical Summary

Problems solved by technology

For example, when etching silicon nitride-silicon oxide stacks (NO pairs) with a thickness of about 5 microns, the thickness of the mask needs to reach the order of microns. Alignment accuracy is compensated so that process results are only known after rework

At the same time, as the structure of 3D NAND devices becomes more complicated, the channel hole (Channel Hole) changes from single etching to secondary deposition and secondary etching. Increasing and becoming more serious problems such as hole tilting (tilting) are further compressing the process window and affecting the yield of semiconductor devices

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