Cu-Cu Bonded Semiconductor Structure With Guard Rings Against Voids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Cu—Cu junction in semiconductor devices is prone to dishing, concavities, voids, and corrosion, leading to reduced junction strength and reliability, especially during dicing and exposure to moisture, which can cause inner cracks and chipping.
Innovation Solution
A semiconductor device design incorporating multiple guard rings and Cu dummies on the junction surfaces, with specific configurations to enhance junction strength and prevent moisture infiltration, including guard ring units with grooves and slits to surround power source pads and the scribe line, and Cu dummies on the outer circumference to reinforce bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a guard ring is formed on a Cu-Cu junction surface to improve connection strength, then junction strength is improved, but dishing occurs and concavities and convexities are easily formed on the junction surface
Solution Approach 1:
The patent applies different structures to different locations: a first guard ring is formed on the first semiconductor substrate, a second guard ring is formed on the second semiconductor substrate, and a third guard ring is formed on the junction surface. This localized differentiation allows each guard ring to address specific local issues without causing global dishing problems.
Solution Approach 2:
The guard ring structure is segmented into three separate components (first guard ring, second guard ring, third guard ring) rather than using a single continuous guard ring. This segmentation distributes the structural support and prevents the formation of large concavities and convexities on the junction surface.
2Strength
If a guard ring is formed on a Cu-Cu junction surface, then connection strength is improved, but voids are easily generated which decrease junction strength
Solution Approach 1:
The third guard ring is specifically positioned on the junction surface to address local void formation issues, while the first and second guard rings on各自的 substrates prevent excessive stress concentration that could lead to voids.
3Volume of moving object
If the Cu-Cu junction surface is used for joining semiconductor substrates, then space saving is achieved compared to TSV method, but moisture infiltration causes wiring corrosion and reliability degradation
Solution Approach 1:
The guard rings act as intermediary protective structures between the Cu-Cu junction surface and the external environment. They create a barrier that prevents moisture from reaching and corroding the copper electrodes and wiring, thereby protecting the electrical connections.
Solution Approach 2:
The guard rings are formed in advance before moisture infiltration can occur, creating a preventive barrier against corrosion. This preliminary protective action stops moisture from reaching the vulnerable Cu-Cu junction and wiring structures.
Data Source
AI summary
A semiconductor device includes a first semiconductor substrate, a second semiconductor substrate, and at least one guard structure including a first guard element, a second guard element, and a third guard element. The first semiconductor substrate and the second semiconductor substrate are bonded to one another at a bonding interface between a surface of the first semiconductor substrate and a surface of the second semiconductor substrate. The first guard element is in the first semiconductor substrate and spaced apart from the third guard element by a portion of the first semiconductor substrate. The second guard element is in the second semiconductor substrate and spaced apart from the third guard element by a portion of the second semiconductor substrate, and the third guard element includes portions in the first surface and the second surface to bond the first semiconductor substrate to the second semiconductor substrate.