Laser-Guided Wafer Separation for Precise Planar Modifications
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Solution Overview
Problem
Traditional methods for cutting semiconductor wafers, such as inner diameter saws and guided wires, result in variations in thickness and surface deviations due to mechanical limitations, requiring extensive post-processing to achieve planarity and efficiency, while existing planarization methods are costly and inefficient for large wafers.
Innovation Solution
A method and device using a laser processing system that adjusts focus based on real-time parameters like refractive index and processing depth, with a receiving layer of polymer-hybrid material to guide crack propagation for precise separation of solid-state components, allowing for continuous adjustment and correction of laser beams to maintain planarity and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional mechanical cutting methods (inner diameter saws or guided wires) are used to cut semiconductor wafers, then the cutting process can be performed, but variations in thickness and surface deviations occur due to mechanical limitations
Solution Approach 1:
The patent replaces the traditional mechanical cutting system (saws or guided wires) with a laser-based system. The laser creates modifications in the solid state that guide crack propagation, enabling separation without mechanical contact. This substitution eliminates the mechanical limitations that cause thickness variation and surface deviations, achieving superior manufacturing precision while maintaining ease of manufacture.
Solution Approach 2:
The patent changes the physical state and properties of the material being cut by using laser-induced modifications rather than mechanical force. By creating a laser-damage layer and inducing controlled cracks through optical energy, the process achieves precise separation with minimal surface deviation, resolving the contradiction between ease of manufacture and manufacturing precision.
2Manufacturing precision
If planarization and polishing steps are performed after cold split method to remove surface deviations, then surface quality is improved, but material efficiency decreases due to loss of reserve in planarization slicing
Solution Approach 1:
The patent performs the separation action preliminarily through laser-induced crack propagation before any planarization is needed. By creating precise modifications that guide crack separation at the exact desired location, the process eliminates the need for subsequent planarization slicing, thereby maximizing material efficiency while achieving the required surface planarity.
Solution Approach 2:
The patent replaces mechanical planarization slicing with a laser-based separation process that creates precise modifications guiding crack propagation. This substitution eliminates material loss associated with traditional planarization steps while maintaining surface quality, directly resolving the contradiction between manufacturing precision and material efficiency.
3Manufacturing precision
If mechanical wedge compensation is used to achieve planarity, then some planarity correction is possible, but only limited extent and only static applications can be implemented
Solution Approach 1:
The patent introduces dynamic adaptability through real-time parameter adjustment during laser processing. The system continuously adjusts laser parameters based on real-time feedback about the workpiece geometry and material properties, enabling dynamic correction of planarity issues rather than relying on static mechanical wedge compensation. This allows the process to adapt to varying conditions while maintaining high manufacturing 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
This approach significantly increases material efficiency and reduces reworking effort by enabling precise planarization and separation of large wafers with minimal surface deviations, improving overall yield and reducing processing costs.
Implementation Method 1
A method and device for producing planar modifications in solid bodies... creating modifications in a solid state... defined focusing of the laser beams... for creation of a modification within a solid state
Implementation Method 2
the laser processing system is adjusted continuously as a function of at least one parameter and preferably as a function of a plurality of parameters, in particular at least two parameters, for defined focusing of the laser beams... first parameter is the average refractive index of the material of the solid state
Data Source
AI summary
A method for creating modifications in a solid-state material is described, wherein a crack guidance region for guiding a crack for separating a solid-state layer from the solid-state material is predetermined by the modifications. The method includes: moving the solid-state material relative to a laser processing system; successively emitting a plurality of laser beams from the laser processing system to the solid-state material to create at least one modification within the solid-state material; and continuously adjusting the laser processing system for defined focusing of the plurality of laser beams and/or for adjustment of energy of the plurality of laser beams as a function of at least one parameter.