Three-dimensional memory and manufacturing method thereof

Abstract

The invention relates to a three-dimensional memory and a manufacturing method thereof. The manufacturing method of the three-dimensional memory comprises the steps of forming a first stack structureon a substrate; forming a first channel hole passing through the first stack structure; forming a protective layer at least covering the edge of the substrate, wherein the protective layer is made ofmetal silicide; and forming a channel structure in the first channel hole, thereby enabling the edge of the substrate to be covered with the metal silicide as a protective layer in the etching step, preventing the edge of the substrate from being damaged by an etching agent, and improving the yield of the three-dimensional memory.

Description

【Technical field】 [0001] The invention relates to the technical field of memory, in particular to a three-dimensional memory and a manufacturing method thereof. 【Background technique】 [0002] As technology develops, the semiconductor industry is constantly looking for new production methods to allow each memory die in a memory device to have a greater number of memory cells. Among them, 3D NAND (three-dimensional) memory has become a cutting-edge three-dimensional memory technology with great development potential due to its advantages of high storage density and low cost. [0003] In 3D NAND memory, multiple levels of stacks (decks) can be stacked to increase storage density. Each stack includes a gate stack structure and a channel pillar extending through the gate stack structure, the gate stack structure is used to provide the gate conductor of the selection transistor and the storage transistor, and the channel pillar is used to provide the channel layer and the channe...

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Problems solved by technology

[0004] However, in the etching step of removing the sacrificial layer, the etchant will cause damage to the edge of the substrate in addition to removing the sacrificial layer, so that the thickness of the clamping region at the edge of the substrate is reduced and the mechanical strength is reduced, resulting in a substrate Stuck on the wafer holder, difficult to remove, or cause the substrate edge to shatter and contaminate the equipment

Therefore, substrate edge damage is an important reason for the decrease in the yield of 3D memory

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