Multi-Die-to-Wafer Hybrid Bonding for Precise 3D IC Alignment
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Solution Overview
Problem
Current die-to-wafer bonding technologies face challenges with alignment accuracy, defect rates, and complexity in stacking and bonding small IC dies, leading to lower yields and increased time consumption compared to wafer-to-wafer bonding.
Innovation Solution
A high-precision die-to-wafer bonding method involving precise alignment structures and simultaneous multi-die picking and placing of individual dies from a die-source wafer onto a recipient wafer, allowing for testing and selection of known-good dies before bonding, which improves alignment accuracy and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If die-to-wafer bonding is used to reduce 2-D footprint, then integration density is improved, but alignment accuracy deteriorates (5-10 μm vs 1 μm)
Solution Approach 1:
The patent applies preliminary action by performing alignment marking and registration structure formation on the recipient wafer before the actual die placement process. This pre-establishment of alignment references enables higher precision positioning during subsequent die-to-wafer bonding, resolving the alignment accuracy deterioration while maintaining reduced 2-D footprint benefits
2Adaptability or versatility
If individual dies are manipulated and aligned for die-to-wafer bonding, then integration flexibility is improved, but processing time increases
Solution Approach 1:
The patent merges multiple individual die placement operations into a simultaneous multi-die bonding process. By coordinating the placement of multiple dies in parallel using integrated alignment structures, the system maintains integration flexibility while significantly reducing the cumulative processing time associated with sequential manipulation and alignment of individual dies
3Device complexity
If defects are additive in wafer-to-wafer bonding, then defect rate increases, but testing complexity is reduced
Solution Approach 1:
The patent applies preliminary action by implementing defect screening and selection of known-good dies before the bonding process. This pre-bonding inspection and selection step prevents defective dies from being bonded, thereby reducing the cumulative defect rate while maintaining manageable testing complexity through targeted pre-screening rather than post-bonding verification
Data Source
AI summary
Integrated circuit structures and methods for a high precision die-to-wafer bonding technology for fabricating 3-D stacked IC dies. Embodiments include precise alignment structures and methods, and also provide fast fabrication techniques using simultaneous multi-die picking and placing of individual dies from a die-source wafer onto a recipient wafer. Stacked-die yields are improved over wafer-to-wafer bonding technologies by enabling testing and selection of known-good die-source dies before bonding onto the recipient wafer, and by providing optional physical alignment structures on the recipient wafer and/or die-source wafer. Embodiments enable, for example, fabrication of high-power, high-performance devices on ICs formed on GaAs or GaN die-source wafers and bonding individual die-source IC dies to ICs that include CMOS control and driver circuitry formed on an SOI recipient wafer. The resulting 3-D stacked IC dies may offer advantages that include scalability, reliability, and form-factor reduction.