Yangtze Memory Technologies Co., Ltd.

Xiangning Wang

Zhu Yang

Jingjing Geng

Bin Yuan

Chen Zuo

Zongke Xu

Qiangwei Zhang

Zhen Guo

Xinxin Liu

Wei Xu

ZongLiang Huo

Zhipeng Wu

Lu Zhang

Kai Han

Jiajia Wu

Meng Xiao

Hang Yin

Pan Wang

Hui Zhang

Liming Cheng

Beibei Li

Embodiments of a three-dimensional (3D) memory device and fabrication methods thereof are disclosed. In an example, a 3D memory device includes a memory stack having a plurality of stairs. Each stair may include interleaved one or more conductor layers and one or more dielectric layers. Each of the stairs includes one of the conductor layers on a top surface of the stair, the one of the conductor layers having (i) a bottom portion in contact with one of the dielectric layers, and (ii) a top portion exposed by the memory stack and in contact with the bottom portion. A lateral dimension of the top portion may be less than a lateral dimension of the bottom portion. An end of the top portion that may be facing away from the memory stack laterally exceeds the bottom portion by a distance.

Method and structure for forming stairs in three-dimensional memory devices

A semiconductor device includes a stack of alternating word line layers and insulating layers. The stack includes a core area, a stair step area, and, optionally, a dummy transition area connecting the core area to the stair step area. The semiconductor device also includes a gate line (GL) trench through the stack extending from the core area through the dummy transition area to the stair step area. The GL trench has a first width within the core area and a second width within the stair step area that is different from the first width. The semiconductor device also includes a first channel structure formed through the stack within the core area, and a stair step contact (SCT) formed through at least a portion of the stack within the stair step area. The SCT connects one of the word line layers of the stack within the stair step area.

Gateline mask design for removing sacrificial gateline polysilicon within stair step area

A three-dimensional (3D) memory device includes a staircase, a plurality of contacts, a plurality of groups of support structures, and a fourth support structure between adjacent groups of support structures through the staircase. The plurality of groups of support structures are arranged in a first direction. Each of the groups of support structures includes three support structures. Projections of the three support structures form a triangular shape in a plane parallel to the first direction. The plurality of contacts each is surrounded by a respective group. A projection of one of the contacts overlaps with the triangular shape of the respective group.

Three-dimensional memory devices and methods for forming the same

Aspects of the disclosure provide methods for fabricating semiconductor devices. In some examples, a method for fabricating a semiconductor device includes forming a stack of layers having a first region and a second region. The stack of layers includes at least a first layer. The method then forms a hard mask layer on the stack of layers in the first region. Then, the method includes patterning the stack of layers in the second region of the semiconductor device. The patterning of the stack of layers in the second region removes a portion of the stack of layers in the second region, and exposes a side of the stack of layers. The method further includes covering at least the side of the stack of layers with a second layer that has a lower remove rate than the first layer, and then the method includes removing the hard mask layer.

Semiconductor device fabrication

The present disclosure provides a method for forming a three-dimensional (3D) memory. In an example, the method includes forming a stack structure having interleaved a plurality of stack first layers and a plurality of stack second layers, forming a stair in the stack structure, the stair having one of the stack first layers on a top surface, and forming a layer of sacrificial material having a first portion over a side surface of the stair and a second portion over the top surface of the stair. The method also includes partially removing the first portion of the layer of sacrificial material using an anisotropic etching process and removing a remaining portion of the first portion of the layer of sacrificial material using an isotropic etching process.

Methods for forming stairs in three-dimensional memory devices

Aspects of the disclosure provide semiconductor devices. For example, a semiconductor device includes a substrate having a first region and a second region along a first direction that is parallel to a main surface of the substrate. Then, the semiconductor device includes a memory stack that includes a first stack of alternating gate layers and insulating layers and a second stack of alternating gate layers and insulating layers along a second direction that is perpendicular to the main surface of the substrate. Further, the semiconductor device includes a joint insulating layer in the second region and a third stack of alternating gate layers and insulating layers in the first region between the first stack of alternating gate layers and insulating layers and the second stack of alternating gate layers and insulating layers.

Vertical memory devices

Aspects of the disclosure provide a method for fabricating a semiconductor device having an first stack of alternating insulating layers and sacrificial word line layers arranged over a substrate, the first stack including a core region and a staircase region. The method can include forming a first dielectric trench in the core region of the first stack, forming a second dielectric trench that is adjacent to and connected with the first dielectric trench in the staircase region of the first stack, and forming dummy channel structures extending through the first stack where the dummy channel structures are spaced apart from the second dielectric trench.

Method of forming top select gate trenches

Embodiments of a three-dimensional (3D) memory device and fabrication methods thereof are disclosed. In an example, a method for forming a 3D memory device includes the following operations. A dielectric stack is formed to have interleaved sacrificial layers and dielectric layers. A stair is formed in the dielectric stack. The stair includes one or more sacrificial layers of the sacrificial layers and one or more dielectric layers of the dielectric layers. The stair exposes one of the sacrificial layers on a top surface and the one or more sacrificial layers on a side surface. An insulating portion is formed to cover the side surface of the stair to cover the one or more sacrificial layers. A sacrificial portion is formed to cover the top surface of the stair. The sacrificial portion is in contact with the one of sacrificial layers. The one or more sacrificial layers and the sacrificial portion are replaced with one or more conductor layers.

A three-dimensional (3D) memory device is provided. In an example, the 3D memory device includes a staircase and a plurality of groups of support structures through the staircase. The plurality of groups of support structures are arranged in a first direction, and each of the groups of support structures comprises three support structures, wherein projections of the three support structures form a triangular shape in a plane parallel to the first direction.

Embodiments of three-dimensional (3D) memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a substrate, a memory stack on the substrate, a plurality of channel structures each extending vertically through the memory stack, an isolation structure, and an alignment mark. The memory stack includes a plurality of interleaved conductive layers and dielectric layers. An outmost one of the conductive layers toward the substrate is a source select gate line (SSG). The isolation structure extends vertically into the substrate and surrounds at least one of the channel structures in a plan view to separate the SSG and the at least one channel structure. The alignment mark extends vertically into the substrate and is coplanar with the isolation structure.

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Wuhan, China

Xiangning Wang