Wafer Bonding Trenches for Reliable Pad Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for bonding wafers in semiconductor device manufacturing often result in improper electrical connection between metal pads due to surface depressions or projections, leading to increased electric resistance or open defects.
Innovation Solution
The formation of trenches in the wafers allows for the use of a plating solution to electrically connect metal pads via electroless plating, ensuring proper joining even when surfaces are depressed or projected, and subsequent embedding with insulating material to maintain connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wafer bonding methods are used, then the manufacturing process is simple, but electrical connection between metal pads deteriorates due to surface depressions or projections
Solution Approach 1:
Trenches are formed in the wafers before bonding to pre-establish pathways for electrical connection. This preliminary action ensures that even if surface depressions or projections occur during bonding, the metal pads remain aligned through the trenches, maintaining reliable electrical connection while managing the complexity of the manufacturing process.
2Productivity
If surface depressions or projections occur during bonding, then bonding speed is maintained, but electrical connection quality deteriorates
Solution Approach 1:
The trenches act as intermediaries between the metal pads on opposing wafers. By providing a defined pathway through the wafer thickness, the trenches mediate the electrical connection, ensuring that surface irregularities during bonding do not disrupt pad alignment or connection quality, thus maintaining both productivity and reliability.
3Reliability
If trenches are formed in wafers to ensure electrical connection, then electrical connection reliability improves, but manufacturing process complexity increases
Solution Approach 1:
The wafer structure is segmented by forming trenches that divide the wafer into distinct regions. This segmentation creates dedicated pathways for electrical connection, isolating the metal pads and ensuring reliable electrical connection. The segmented structure manages manufacturing complexity by providing a clear, repeatable pattern that can be integrated into existing fabrication processes.
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
This method effectively reduces electric resistance and prevents open defects by ensuring reliable electrical connections between metal pads, enhancing the manufacturing process of semiconductor devices.
Implementation Method 1
the use of a plating solution to electrically connect metal pads via electroless plating
Data Source
AI summary
In one embodiment, a semiconductor device includes a first wafer or a first chip including a first insulator and a first pad. The device further includes a second wafer or a second chip including a second insulator in contact with the first insulator, and a second pad opposed to the first pad and electrically connected to the first pad. Moreover, the first insulator includes a first trench extending to the first pad, and/or the second insulator includes a second trench extending to the second pad.