Dummy Pad Layout for Semiconductor Bonding Reliability
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Solution Overview
Problem
Existing semiconductor devices face issues with un-bonding and failure in electric connection structures during the bonding process of sub-chips, leading to reduced yield and reliability.
Innovation Solution
Incorporation of dummy pads and guard ring structures in the edge regions of semiconductor devices, which are electrically isolated from metal pads, to prevent un-bonding and provide a diffusion path for hydrogen ions, improving electrical and operational characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dummy pads are added to the edge region, then bonding reliability is improved, but device complexity increases
Solution Approach 1:
Dummy pads are created as copies of functional metal pads but placed in the edge region where they serve a different purpose - providing bonding surface area without electrical connection. This allows the bonding process to be more reliable without adding complex electrical interconnections, as the dummy pads replicate the physical bonding interface without the electrical complexity.
Solution Approach 2:
The dummy pads act as intermediary elements between the metal pads and the edge region structure. They provide a transition zone that improves bonding reliability by distributing stress and providing additional bonding surface area, while the insulating structure acts as an intermediary that electrically isolates these dummy pads from the functional circuitry.
2Reliability
If dummy pads are electrically isolated from metal pads, then bonding failures are reduced, but manufacturing precision requirements increase
Solution Approach 1:
The insulating structure serves as an intermediary element that provides clear physical and electrical separation between the metal pads and dummy pads. This intermediary layer makes the alignment requirements more manageable by providing a distinct boundary, allowing the dummy pads to be positioned in the edge region without requiring extremely precise alignment with the functional metal pads.
Solution Approach 2:
The bonding interface is segmented into functional metal pads in the device region and dummy pads in the edge region, separated by insulating structures. This segmentation allows each region to be optimized independently - the metal pads for electrical connectivity and the dummy pads for bonding reliability - without requiring perfect alignment between them, thus reducing manufacturing precision requirements.
3Reliability
If guard ring structures are extended into the second insulating structure, then hydrogen ion diffusion is improved, but device complexity increases
Solution Approach 1:
The guard ring structure is designed to serve multiple functions: it provides electrical isolation, facilitates hydrogen ion diffusion through the insulating structure, and strengthens the bonding interface. By making the guard ring multi-functional, the patent improves electrical performance and bonding reliability without requiring additional separate structures, thus avoiding increased device complexity.
Solution Approach 2:
The guard ring structure is merged with the insulating structure by extending into it, creating a unified element that performs both mechanical bonding support and chemical functions (hydrogen ion diffusion). This merging eliminates the need for separate structures for each function, improving electrical performance while maintaining structural simplicity.
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
The implementation of dummy pads and guard ring structures enhances the reliability of semiconductor devices by preventing un-bonding and failure in electric connections, thereby increasing yield and improving electrical performance.
Implementation Method 1
providing a diffusion path for hydrogen ions
Data Source
AI summary
A semiconductor device may include a first substrate including device and edge regions, a first insulating structure on the first substrate, first metal pads and first dummy pads at the uppermost end of the first insulating structure, a second insulating structure on the first insulating structure, second metal pads and second dummy pads at the lowermost end of the second insulating structure, a first interconnection structure in the first insulating structure, electrically connected to the first metal pads and electrically isolated from the first dummy pads, and a second interconnection structure in the second insulating structure, electrically connected to the second metal pads, and electrically isolated from the second dummy pads. Ones of the first metal pads may be in contact with respective ones of the second metal pads on the device region, and ones of the first dummy pads may be in contact with respective ones of the second dummy pads on the edge region.