Three-dimensional memory and preparation method thereof

Abstract

The invention belongs to the technical field of memory equipment, and particularly relates to a three-dimensional memory and a preparation method of the three-dimensional memory. The three-dimensionalmemory comprises a substrate, a stack structure arranged on the substrate, and a channel structure penetrating through the stack structure and extending into the substrate. A substrate epitaxial layer is arranged between the substrate and the stack structure; the functional layer is provided with a gap, and the side wall of part of the channel layer exposed in the gap is provided with a conductive semiconductor layer; and a channel epitaxial layer is arranged on the conductive semiconductor layer and is connected with the substrate epitaxial layer. The risk of channel disconnection caused bythe fact that the channel layer is easily etched by hydrochloric acid when the channel layer is prepared by adopting a silicon epitaxial growth method in the prior art is overcome.

Description

technical field [0001] The invention relates to the technical field of memory, in particular to a three-dimensional memory and a preparation method of the three-dimensional memory. Background technique [0002] With the rapid development of technologies such as big data, cloud computing, and the Internet of Things, the requirements for memory integration and storage density have also increased. Traditional two-dimensional planar memory has been difficult to meet actual needs and is gradually being replaced by three-dimensional memory. [0003] In the related art, a three-dimensional memory includes a substrate provided with an epitaxial layer, and a stack structure provided on the epitaxial layer. The stack structure is provided with a channel hole penetrating the stack structure, and a functional layer and a channel layer are provided in the channel hole. , the channel layer is electrically connected to the bit line (abbreviated as BL) at the top of the stack structure and ...

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Problems solved by technology

[0004] However, when growing the epitaxial layer, the silicon source dichlorodihydrogen silicon (SiH 2 Cl 2 , referred to as DCS) decomposition of the by-product hydrochloric acid (HCl) on the polysilicon (poly) on the sidewall of the channel layer etch faster, resulting in poor uniformity of polysilicon on the sidewall of the channel layer; in addition, in the epitaxy During the growth process of the channel layer, the polysilicon epitaxial growth rate on the sidewall of the channel layer is relatively slow; the above two conditions lead to the epitaxial layer on the sidewall of the channel layer being thinner than the epitaxial layer on the substrate, resulting in the subsequent use of in-situ water vapor generation (In-Situ Stream Generation, referred to as ISSG) method to prepare the channel layer, there is a risk of channel layer disconnection

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