3D Semiconductor Contact Structure for Misalignment-Tolerant Stacking
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Solution Overview
Problem
The increasing complexity of semiconductor devices, particularly in three-dimensional structures, poses challenges in achieving reliable connections and stable structures due to limitations in unit memory cell integration and manufacturing methods.
Innovation Solution
The semiconductor device incorporates alternately stacked insulating and sacrificial layers with protruding contact structures to ensure reliable connections between peripheral circuits and channel structures, using interlayer insulating layers to facilitate contact formation despite potential misalignment during manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If three-dimensional stacked structures are used to improve integration density, then the degree of integration is improved, but manufacturing precision and connection reliability deteriorate due to alignment difficulties
Solution Approach 1:
The protruding part is formed in advance during the first contact structure fabrication process, before the second contact structure is created. This preliminary formation ensures that the alignment reference is already in place, allowing subsequent layers to be accurately positioned relative to it, thereby solving the alignment precision issue in 3D stacked structures
Solution Approach 2:
The protruding part acts as an intermediary element between the first contact structure and the second contact structure. It provides a physical and electrical bridge that facilitates accurate alignment and reliable connection between the stacked contact structures, addressing both the connection reliability and alignment precision challenges
2Reliability
If complex stacked structures with multiple contact structures are implemented, then connection reliability is improved, but device complexity increases
Solution Approach 1:
The contact structure is divided into multiple segments: the first contact structure extending through the first interlayer insulating layer, the protruding part extending from its sidewall, and the second contact structure connected to the protruding part. This segmentation allows each component to be optimized independently while working together to achieve reliable connections in the 3D stacked architecture
Solution Approach 2:
The contact structures extend in multiple dimensions - the first contact structure extends vertically through the first interlayer insulating layer, while the protruding part extends horizontally from the sidewall. This multi-dimensional arrangement enables reliable connections without requiring excessive horizontal space, managing device complexity while improving connection reliability
Data Source
AI summary
A semiconductor device includes a stack disposed over a peripheral circuit. The stack includes alternately stacked insulating layers and sacrificial layers. The semiconductor device also includes a first contact structure penetrating through the stack to connect with the peripheral circuit. The first contact structure includes a protruding part extending outward from a sidewall of the first contact structure. The semiconductor device further includes a second contact structure disposed on the first contact structure. The second contact structure is connected to the protruding part of the first contact structure.