3D Memory Through-Contact Layout Using Sacrificial Insulating Layers
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Solution Overview
Problem
In semiconductor memory devices, the formation of memory holes with a high aspect ratio is challenging due to the lamination of conducting layers and interlayer insulating layers, which can lead to increased inner diameters of contact holes and longer distances between through contacts, affecting the efficiency and area of the through contact region.
Innovation Solution
The use of a sacrificial layer as an insulating layer between contacts eliminates the need for additional insulating layers within contact holes, reducing the distance between through contacts and decreasing the area of the through contact region, and the deployment of stopper insulating layers to control chemical etching progress accurately sets the position and area of the through contact region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conducting layers and interlayer insulating layers are laminated to form memory holes, then the memory structure is achieved, but the inner diameter of contact holes increases and the distance between through contacts increases
Solution Approach 1:
The patent extracts and removes the insulating layer from within the contact hole after the memory hole formation process. This extraction eliminates the need for additional insulating layers in the contact hole region, thereby reducing the inner diameter of contact holes and minimizing the distance between through contacts, which directly resolves the technical contradiction.
Solution Approach 2:
The patent applies a sacrificial insulating layer during the memory hole formation process, which is then removed in a subsequent step. This preliminary action allows the memory structure to be formed correctly while enabling the later removal of the insulating layer to reduce contact hole dimensions and optimize through contact spacing.
2Reliability
If additional insulating layers are placed within contact holes, then insulation is provided, but the area of the through contact region increases
Solution Approach 1:
The patent removes the insulating layer from the contact hole region after memory hole formation, extracting only the necessary portion. This selective extraction maintains insulation where needed for memory functionality while eliminating insulating material in the contact hole area, thereby reducing the through contact region area without compromising insulation quality in critical areas.
Solution Approach 2:
The patent applies different treatments to different regions: the insulating layer is retained in the memory hole region to provide necessary insulation, but removed in the contact hole region to minimize area. This local differentiation of insulating layer presence optimizes both insulation quality and contact region area.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces the area of the through contact region, enhances processing convenience, and facilitates faster voltage transfer to conducting layers by minimizing wiring resistance and eliminating the need for additional insulating layers within contact holes.
Implementation Method 1
the deployment of stopper insulating layers to control chemical etching progress accurately sets the position and area of the through contact region
Data Source
AI summary
According to one embodiment, a semiconductor memory device includes a substrate having a first region and a second region arranged in a first direction. The first region includes word line layers and interlayer insulating layers laminated in a second direction, a first semiconductor layer opposed to the word line layers, and an electric charge accumulating film disposed between them. The second region includes a part of the word line layers and the interlayer insulating layers, first insulating layers and a part of the interlayer insulating layers that separate from the word line layers, a contact that has an outer peripheral surface connected to the first insulating layers, and a second insulating layer disposed between the word line layers and the first insulating layers. The first insulating layers have side surfaces connected to the word line layers and side surfaces connected to the second insulating layer.