Laser Wafer Modification Layer Control for Eccentricity Correction
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Solution Overview
Problem
Existing wafer separation and edge trimming processes are compromised by eccentric formation of modification layers, leading to improper separation and removal of peripheral portions in semiconductor wafers.
Innovation Solution
A wafer processing system with a modifying apparatus that forms non-bonding regions, peripheral, internal, and central modification layers using laser light to correct eccentricity, ensuring precise removal and separation by controlling the formation of these layers in a spiral and concentric manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser light is radiated to form internal modification layers in a single crystalline substrate, then the substrate can be separated and peripheral portions can be removed, but eccentric formation of modification layers occurs leading to improper separation and removal
Solution Approach 1:
The patent applies asymmetry by intentionally creating an asymmetric support structure where the support portion extends further than the susceptor in specific directions. This asymmetric design compensates for the eccentric formation of internal modification layers by providing extended support coverage in the regions where modification layers tend to form eccentrically, thereby ensuring uniform separation and removal quality across the entire substrate surface despite the eccentric modification layer formation
Solution Approach 2:
The patent changes the geometric parameters of the support structure by adjusting the extension length and direction of the support portion relative to the susceptor. By optimizing these parameters, the support structure compensates for eccentric modification layer formation, ensuring that separation and removal operations proceed uniformly across the substrate even when modification layers are not perfectly centered
2Manufacturing precision
If the holder and processing target object have eccentric alignment, then the internal modification layers are formed improperly, but correcting the alignment increases process complexity
Solution Approach 1:
The patent implements preliminary action by pre-configuring the support structure with an asymmetric design before the laser processing begins. The support portion is intentionally extended beyond the susceptor in specific directions to anticipate and compensate for the eccentric modification layer formation. This preliminary structural preparation eliminates the need for complex real-time alignment control mechanisms during the laser processing operation
Solution Approach 2:
The asymmetric support structure serves itself by automatically compensating for alignment errors through its geometric design. The extended support portion inherently provides the necessary support coverage in eccentric regions without requiring active sensing or adjustment mechanisms, allowing the system to self-correct for misalignment issues
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 accurate and efficient separation and edge trimming of semiconductor wafers by correcting eccentricity, maintaining quality and completeness of peripheral and central removal processes.
Implementation Method 1
a modifying device configured to radiate laser light to an inside of the processing target object to form multiple internal modification layers
Implementation Method 2
the internal modification layer is formed by changing a single crystalline structure of the substrate into a polycrystalline structure
Data Source
AI summary
A processing apparatus configured to process a processing target object includes a holder configured to hold the processing target object; a modifying device configured to radiate laser light to an inside of the processing target object to form multiple internal modification layers; and a controller. The controller controls an operation of forming the internal modification layers such that the internal modification layers are formed in a spiral shape from a diametrically outer side of the processing target object toward a diametrically inner side thereof, and such that an eccentric amount between the holder and the processing target object held by the holder in the forming of the internal modification layers toward the diametrically inner side of the processing target object becomes smaller than the eccentric amount in forming the internal modification layers toward the diametrically outer side of the processing target object.