Uniform Metal Layer for TSV Etching Control
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Solution Overview
Problem
The integration of wafers with metal layers made of different materials complicates the etching process, leads to cross contamination during cleaning, and results in poor contact performance between the interconnection layer and the metal layers in semiconductor devices.
Innovation Solution
A manufacturing method where a uniform metal layer, made of the same material as the first metal layer, is formed above the second metal layer, allowing for controlled etching and avoiding cross contamination by ensuring the interconnection layer is electrically connected to both metal layers, which are made of the same material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If metal layers of different materials are simultaneously exposed in the TSV hole to achieve inter-wafer interconnection, then the interconnection layer can be electrically connected to metal layers of different wafers, but the etching process difficulty increases and cross contamination occurs in the cleaning process
Solution Approach 1:
An intermediate metal layer is introduced between the first metal layer and the second metal layer. This intermediate layer serves as a mediator that can be selectively etched while protecting the underlying metal layers, enabling controlled exposure of specific metal layers without causing cross contamination or increasing etching complexity
Solution Approach 2:
The TSV structure is segmented into multiple sections with different metal layers at different depths. The intermediate metal layer is positioned at a specific depth to enable selective electrical connections, allowing the interconnection layer to connect to different metal layers in different wafers through controlled etching of specific segments
2Adaptability or versatility
If metal layers of different materials are simultaneously exposed in the TSV hole to achieve inter-wafer interconnection, then the interconnection layer can be electrically connected to metal layers of different wafers, but cross contamination occurs in the cleaning process
Solution Approach 1:
The intermediate metal layer acts as a protective intermediary during the cleaning process. It can be selectively removed or protected during cleaning operations, preventing cleaning agents from causing cross contamination between different metal layers while maintaining interconnection functionality
Solution Approach 2:
The intermediate metal layer is formed in advance before the interconnection layer is deposited. This preliminary structure enables controlled cleaning operations to be performed without directly exposing and contaminating the sensitive metal layers that require different cleaning conditions
3Adaptability or versatility
If metal layers of different materials are simultaneously exposed in the TSV hole to achieve inter-wafer interconnection, then the interconnection layer can be electrically connected to metal layers of different wafers, but the contact performance between the interconnection layer and the metal layers deteriorates
Solution Approach 1:
The intermediate metal layer is made of the same material as the first metal layer, creating a homogeneous material interface. This homogeneity ensures excellent electrical contact performance between the interconnection layer and the metal layers, as the same material interfaces provide consistent and reliable electrical properties without the variability introduced by dissimilar material contacts
Data Source
AI summary
A semiconductor device and a manufacturing method thereof are disclosed. In which a uniform metal layer is formed above the second metal layer of the second wafer, the uniform metal layer is electrically connected to the second metal layer, and the uniform metal layer and the first metal layer are made of the same material. The uniform metal layer and the first metal layer simultaneously exposed by the subsequently formed TSV hole are made of the same material, the degree of over-etching is relatively easy to control in the etching process, and cross contamination of cleaning agents in the cleaning process can be avoided. In addition, when the interconnection layer is electrically connected to the first metal layer and the uniform metal layer, since the uniform metal layer and the first metal layer are made of the same material, the interconnection layer has better contact performance with the two.