Semiconductor Device Supporting Unit Prevents Layer Collapse
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Solution Overview
Problem
In semiconductor device manufacturing, forming through holes in stacked bodies with alternately layered conductive and insulating layers is challenging, leading to partial collapse of conductive layers due to the removal of sacrificial layers, especially around lithographic or inspection marks.
Innovation Solution
A supporting unit is provided around marks on the semiconductor device's surface, extending in the stacked direction and in contact with conductive layers, to prevent collapse by using materials with lower etching rates than sacrificial layers, such as silicon nitride, and designed to be minimally visible or removable in imaging processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If sacrificial layers are removed by substitution process to form through holes, then through holes can be formed in stacked body, but conductive layers may partially collapse in portions where marks are provided
Solution Approach 1:
The patent applies preliminary action by forming supporting units around marks before the substitution process removes sacrificial layers. These supporting units are positioned in advance to prevent conductive layer collapse during subsequent sacrificial layer removal, thus solving the problem of maintaining structural integrity while enabling through hole formation.
Solution Approach 2:
The supporting units act as intermediary structures between the marks and the conductive layers. They provide mechanical support to the conductive layers in regions where sacrificial layers are removed, preventing collapse without interfering with the mark functionality or the through hole formation process.
2Manufacturing precision
If supporting units are provided around marks, then conductive layers are prevented from collapsing, but imaging processes may capture unwanted supporting unit structures
Solution Approach 1:
The supporting units are designed with local quality by making their material composition different from surrounding structures. The supporting units contain elements not present in the mark structures, allowing imaging systems to selectively filter or ignore supporting unit signals while capturing mark information, thus preventing supporting units from appearing in imaging results.
Solution Approach 2:
The patent applies a conceptual version of color changes by using material composition differences to create distinguishable signatures. The supporting units are formed with specific materials that have different compositional characteristics, enabling imaging systems to differentiate and exclude supporting unit signals from the final image, similar to how color filtering works in optical systems.
Data Source
AI summary
According to one embodiment, a semiconductor device includes a stacked body in which a plurality of conductive layers and a plurality of insulating layers are alternately stacked. The semiconductor device includes a mark and a supporting unit. The mark is opened onto a surface of the stacked body. The supporting unit is provided around the mark. The supporting unit extends in a stacked direction of the stacked body. The supporting unit is in contact with at least a plurality of conductive layers.