Three-dimensional NAND memory device structure and preparation method thereof

Abstract

The invention provides a three-dimensional NAND memory device structure and a preparation method thereof. The method comprises the following steps: forming a first laminated structure and a second laminated structure with communicated channel holes on a support substrate; forming a functional layer, a channel layer and a filling dielectric on the surface of the channel hole; forming a gate gap; filling a gap insulating layer in the gate gap; removing the support substrate, and forming a third laminated structure on the back surface of the first laminated structure; etching the third laminatedstructure to form a first etching window, and removing the functional layer at the bottom of the first channel hole based on the first etching window; and filling a channel connection layer in the first etching window. The channel connection layer is formed at the corresponding position of the back surface of the channel hole, so that the risk that the functional layer at the connecting part of the upper channel hole and the lower channel hole is damaged when the channel connection layer and the channel layer are connected through a process of punching from the front surface of the channel hole is avoided; and in addition, the process for forming the channel connection layer is low in complexity, easy to control and high in yield.

Description

technical field [0001] The invention relates to the technical field of memory, in particular to a three-dimensional NAND memory device structure and a preparation method thereof. Background technique [0002] The computing environment paradigm has changed to ubiquitous computing systems that can be used anytime, anywhere. Due to this fact, the use of portable electronic devices such as mobile phones, digital cameras, and notebook computers has rapidly increased. These portable electronic devices usually use storage systems with storage devices, ie data storage devices. Data storage devices are used as primary or secondary storage devices in these portable electronic devices. Thus, the reliability and performance of digital data storage, such as storage systems, is critical. These data storage devices using memory devices offer excellent stability, durability, high information access speed, and low power consumption. Examples of data storage devices having these advantage...

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Problems solved by technology

[0006] However, in the process of forming channel holes by using the above multiple stacks, due to the influence of stress and other factors, there will be overlay deviations in the photoresist layer between the channel holes in the upper stack and the channel holes in the lower stack. When the SONO at the bottom of the channel is opened to form a circuit loop between the substrate well layer (usually P well) and the channel layer, it will cause the top layer structure at the lower end of the upper channel hole at the layer-to-layer connection (that is, ONO) Damaged, which reduces the yield rate and reliability failure of the three-dimensional NAND memory device structure

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