Laser Ablation for Semiconductor Wafer Adhesive Removal
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Solution Overview
Problem
In semiconductor manufacturing, adhesives often fail to peel easily from wafers due to irregular features or saw streets, leading to tearing or residue issues during removal.
Innovation Solution
A laser ablation method is used to selectively compromise the adhesive layer's integrity, reducing its adhesion strength and facilitating easier removal by directing a laser beam with specific parameters across the adhesive layer, particularly at the wafer's edge and saw streets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is applied to mount wafer to carrier, then mechanical stability is provided, but adhesive may not peel easily and may tear or leave residue
Solution Approach 1:
The patent applies a release agent to the carrier surface before applying the adhesive. This preliminary action creates a controlled interface that allows the adhesive to bond strongly to the wafer while maintaining ease of removal from the carrier after processing, directly resolving the contradiction between bonding strength and removal ease
Solution Approach 2:
The release agent is applied selectively to specific areas of the carrier where adhesive removal difficulty occurs, such as edge regions and saw street areas. This localized treatment provides different properties in different zones, enabling easy peeling in problematic areas while maintaining strong bonding in device regions
2Strength
If laser parameters are increased to compromise adhesive layer, then adhesion strength is reduced, but risk of damaging semiconductor wafer increases
Solution Approach 1:
The laser is directed selectively at the adhesive layer in specific regions such as edge areas and saw streets, rather than treating the entire wafer surface. This localized laser application reduces adhesion strength only where needed for peeling initiation, while leaving the adhesive intact in device regions and avoiding damage to the semiconductor structures
Solution Approach 2:
The laser treatment is applied partially to only portions of the adhesive layer that require compromise for peeling, rather than treating the entire adhesive layer uniformly. This partial action achieves the necessary reduction in adhesion strength while minimizing energy input and risk of wafer damage
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 allows for the successful removal of the adhesive layer without damaging the underlying semiconductor wafer, reducing the risk of residue and improving the peeling process efficiency.
Implementation Method 1
a laser beam is used to compromise the physical integrity of a portion of the adhesive layer that is connected to a semiconductor wafer
Implementation Method 2
The adhesive layer is lasered to compromise a physical integrity of the adhesive layer
Data Source
AI summary
Various embodiments of semiconductor manufacturing methods include releasing a transparent carrier from a semiconductor wafer assembly that includes a semiconductor wafer in which a plurality of semiconductor devices are formed, an adhesive layer coupled to the semiconductor wafer, a carrier release layer coupled to the adhesive layer, and the transparent carrier coupled to the carrier release layer. The method further includes controlling a laser system to emit a first beam characterized by first laser parameters toward the adhesive layer, where the first laser parameters are selected so that the first beam will compromise a physical integrity of the adhesive layer. The method further includes, after controlling the laser system to emit the first beam toward the adhesive layer, removing the adhesive layer from the semiconductor wafer.