Three-dimensional memory and manufacturing method thereof

Abstract

The invention provides a three-dimensional memory, which comprises a stacking structure, a first grid line notch, a second grid line notch, a first dummy structure, a contact structure and a second dummy structure. The stacking structure is divided into a core region and a step region in the horizontal direction; the first grid line notch and the second grid line notch are arranged in parallel and extend in the first horizontal direction, and the first dummy structure, the contact structure and the second dummy structure are located in the step area and are sequentially arranged in the second horizontal direction. According to the invention, the dummy structure adopts a long-strip groove type design, and the space between the dummy structures is small, so that the stable supporting function of the dummy structures can be ensured. The dummy structure and the contact structure are staggered up and down, and the area, facing the contact structure, of the dummy structure adopts the indented gradual change design, so that alignment offset windows of the contact structure and the dummy structure in two directions can be increased at the same time. The linearly arranged dummy structure avoids the influence of zigzag arrangement on the gate line cut, and is beneficial to reducing the process difficulty of the gate line cut.

Description

technical field [0001] The invention belongs to the technical field of semiconductor integrated circuits, and relates to a three-dimensional memory and a manufacturing method thereof. Background technique [0002] Three-dimensional memory includes 3D NOR (3D or not) flash memory and 3D NAND (3D and not) flash memory. In 3D NOR flash memory, the memory cells are arranged in parallel between the bit line and the ground line, while in 3D NAND flash memory, the memory cells are arranged in series between the bit line and the ground line. 3D NAND flash memory has a low reading speed, but a high writing speed, suitable for storing data, and its advantages are small size and large capacity. [0003] With the increasing number of storage layers of 3D NAND flash memory, the division of channel holes (CH) in the core area and dummy channel holes (Dummy CH, DCH for short) in the step area has become the mainstream trend, and the dummy channel holes in the step area use Silica filled....

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Problems solved by technology

[0005] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a three-dimensional memory and its manufacturing method, which are used to solve the problem of uneven size of gate line cutouts in the prior art, easy contact structure of step regions and dummy channel holes. overlapping issues

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