Semiconductor Workpiece Splitting with Laser-Induced Separation Zones
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Solution Overview
Problem
Existing semiconductor wafer production processes are inefficient and costly due to high kerf-loss during slicing and the complexity of integrating semiconductor work piece splitting into standard manufacturing processes.
Innovation Solution
A method involving the use of at least two laser beams to create a separation zone in semiconductor work pieces by modifying the material's physical properties, followed by applying an external force to propagate cracks along the zone, thereby splitting the work piece into two separate pieces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If standard slicing techniques are used to produce semiconductor wafers, then wafers can be manufactured, but kerf-loss is high and production costs are high
Solution Approach 1:
The patent applies segmentation by dividing the wafer into multiple sections and creating separate separation zones in each section. This allows different processing strategies to be applied to different parts of the wafer, optimizing the balance between reducing kerf-loss and maintaining production efficiency. The segmentation enables selective splitting of wafer sections with device structures from those without, maximizing material utilization.
Solution Approach 2:
The patent employs preliminary action by forming separation zones and modifying material properties before the actual splitting operation. Laser beams are used to pre-heat and modify the semiconductor material in the separation zones, creating controlled regions that facilitate subsequent mechanical splitting. This preliminary modification reduces the force required for splitting and minimizes damage to device structures.
2Productivity
If semiconductor work piece splitting is integrated into standard manufacturing processes, then wafer reuse is enabled, but process complexity increases
Solution Approach 1:
The patent replaces complex mechanical splitting systems with a laser-based approach. Instead of using sophisticated mechanical apparatus to split wafers, the invention uses laser beams to modify material properties and create separation zones, followed by simpler mechanical actions. This substitution reduces overall process complexity while enabling wafer reuse.
Solution Approach 2:
The patent utilizes parameter changes by varying laser beam parameters (intensity, duration, wavelength) to modify the physical and chemical properties of the semiconductor material in separation zones. By controlling these parameters, the process creates optimized separation zones that facilitate splitting without requiring complex process integration, thereby enabling wafer reuse with manageable complexity.
3Loss of substance
If laser beams are used to create separation zones, then material waste is reduced, but risk of damage to device structures increases
Solution Approach 1:
The patent applies local quality by creating separation zones with modified material properties only in specific locations where splitting is needed. The laser beams selectively modify the semiconductor material in separation zones while leaving device structures untouched. This localized modification minimizes material waste and reduces the risk of damage to device structures by concentrating energy only where required.
Solution Approach 2:
The patent introduces separation zones as intermediary regions between the laser beam action and the device structures. These intermediary zones absorb and dissipate laser energy, preventing direct interaction between the laser and device structures. The separation zones act as buffers that protect device structures from laser-induced damage while still enabling effective splitting.
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
Reduces kerf-loss and improves the efficiency of wafer processing by minimizing material waste and damage to device structures, leading to lower production costs and higher quality wafers.
Implementation Method 1
modifying the semiconductor material of the semiconductor work piece at a plurality of targeted positions within the separation zone... which increases thermo-mechanical stress within the separation zone
Implementation Method 2
modifying the semiconductor material... in at least one physical property which increases thermo-mechanical stress within the separation zone
Implementation Method 3
applying an external force or stress to the semiconductor work piece such that at least one crack propagates along the separation zone and the semiconductor work piece splits into two separate pieces
Data Source
AI summary
A method of splitting a semiconductor work piece includes: forming a separation zone within the semiconductor work piece, wherein forming the separation zone comprises modifying semiconductor material of the semiconductor work piece at a plurality of targeted positions within the separation zone in at least one physical property which increases thermo-mechanical stress within the separation zone relative to a remainder of the semiconductor work piece, wherein modifying the semiconductor material in one of the targeted positions comprises focusing at least two laser beams to the targeted position; and applying an external force or stress to the semiconductor work piece such that at least one crack propagates along the separation zone and the semiconductor work piece splits into two separate pieces. Additional work piece splitting techniques and techniques for compensating work piece deformation that occurs during the splitting process are also described.