Eutectic Bonding Carrier for High-Temperature Wafer Support
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Solution Overview
Problem
Current methods for supporting ultra-thin semiconductor wafers, such as adhesive tapes and the TAIKO process, fail to withstand high temperatures, limiting processing capabilities and increasing the risk of wafer damage during handling and testing.
Innovation Solution
A eutectic bonding layer and carrier are used to support the wafer, allowing high-temperature processing and serving as a lower electrode, replacing conventional adhesives and edge ring devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If adhesive tape or glue is used to support the wafer, then the wafer can be supported during backside grinding, but the adhesive cannot withstand high temperatures and will deteriorate above 400°C
Solution Approach 1:
The patent changes the bonding mechanism from adhesive-based to eutectic bonding, which occurs at specific temperature compositions. The eutectic bonding layer is formed by depositing metal layers (such as Au-Si, Ag-Si, or Al-Si systems) that undergo eutectic reaction at controlled temperatures, enabling reliable bonding at high temperatures without adhesive deterioration
Solution Approach 2:
The patent replaces the chemical adhesive bonding system with a thermal eutectic bonding system. Instead of using organic adhesives that fail at high temperatures, the invention uses metal layers that form eutectic bonds through controlled thermal processing, substituting a temperature-resistant bonding mechanism for the temperature-sensitive adhesive system
2Reliability
If the TAIKO process is used to grind only the inner circumference, then warpage risks are reduced, but an edge ring device is required and the wafer center becomes vulnerable to damage
Solution Approach 1:
The eutectic bonding carrier serves multiple functions simultaneously: it provides mechanical support for the entire wafer surface (not just the edge), enables high-temperature processing, and acts as a stable platform for handling and testing. This multi-functional carrier eliminates the need for separate edge ring devices while maintaining wafer integrity throughout the process
Solution Approach 2:
The eutectic bonding layer acts as an intermediary between the wafer and the carrier, providing strong thermal and mechanical coupling. This intermediary layer enables the carrier to support the wafer uniformly across its entire surface, distributing stresses and preventing the center vulnerability issue seen in edge-ring methods
3Manufacturing precision
If the wafer is thinned to ultra-thin dimension (lower than 100 μm), then the profile is reduced to suitable thickness for die assembly, but the wafer becomes more susceptible to damage during handling and processing
Solution Approach 1:
The eutectic bonding layer is formed on the wafer backside before the ultra-thin grinding process. This preliminary bonding provides immediate mechanical support and protection to the wafer during subsequent thinning operations, preventing damage while enabling the achievement of ultra-thin dimensions with high precision
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
Enables high-temperature processing of ultra-thin wafers without damage, enhances bonding strength, and facilitates electrical testing without modifying existing tools.
Implementation Method 1
forming a eutectic bonding layer on the backside of a wafer, attaching a eutectic bonding carrier on the eutectic bonding layer via the eutectic bonding
Implementation Method 2
performing a thermal process to enhance the bonding between the eutectic bonding layer and the wafer
Data Source
AI summary
A wafer with a eutectic bonding carrier and a method of manufacturing the same are disclosed, wherein the wafer comprises a thinned wafer, a eutectic bonding layer formed on the backside of said thinned wafer, a eutectic bonding carrier attached on said eutectic bonding layer, and a plurality of openings formed at the active side of said thinned wafer and exposing said eutectic bonding layer on the backside of said thinned wafer.