Wafer Grinding and Femtosecond Laser Polishing for Crack Removal
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Solution Overview
Problem
The existing methods for semiconductor device fabrication face challenges in completely removing cracks from the surface and inside of wafers during the polishing process, which degrades the reliability of semiconductor elements.
Innovation Solution
A semiconductor device fabrication apparatus and method that incorporates a grinder with femtosecond pulse laser emission to grind and polish the substrate surfaces, followed by the attachment of a die attach film, effectively addressing the crack removal issue by using a multi-step grinding and polishing process with a femtosecond pulse laser to minimize surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polishing process is used on wafer, then manufacturing process is simple, but cracks on surface and inside of wafer cannot be completely removed
Solution Approach 1:
The polishing process is divided into multiple sequential stages: coarse polishing to remove large defects, fine polishing to eliminate smaller cracks, and ultrafine polishing to achieve the highest surface quality. This segmentation allows each stage to target specific defect sizes, effectively removing cracks that a single polishing stage cannot eliminate.
Solution Approach 2:
The patent employs composite polishing systems combining different polishing materials with varying grit sizes and properties. Multiple polishing pads with different material compositions are used in sequence, each optimized for removing specific types and sizes of defects, thereby achieving complete crack removal through the synergistic effect of different materials.
2Manufacturing precision
If multiple grinding parts are used to grind substrate, then surface defects are reduced, but device complexity increases
Solution Approach 1:
The grinding system is segmented into multiple independent grinding parts, each equipped with grinding wheels of different grit sizes. The first grinding part uses coarse grit for initial material removal, the second uses medium grit for intermediate processing, and the third uses fine grit for final surface refinement. This segmentation enables progressive defect removal while maintaining manageable complexity through modular design.
Solution Approach 2:
Each grinding part performs preliminary actions tailored to specific defect types and sizes. The coarse grinding part预先 removes large surface irregularities, the medium grinding part prepares the surface for fine finishing, and the fine grinding part achieves the final precision. This preliminary action approach allows each component to be optimized for its specific function, reducing overall system complexity.
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
The approach enhances the reliability of semiconductor devices by reducing surface and internal defects, improving the precision and effectiveness of the grinding and polishing processes, and preventing heat damage to protective tapes, thereby ensuring higher quality semiconductor elements.
Implementation Method 1
a laser emitter configured to emit a femtosecond pulse laser to the first surface of the substrate transferred from the grinder
Data Source
AI summary
A semiconductor device fabrication apparatus including a grinder comprising a grinding part, the grinding part configured to grind a first surface of a substrate, a laser emitter configured to emit a femtosecond pulse laser to the first surface of the substrate transferred from the grinder, and a mount configured to attach a die attach film to the first surface of the substrate transferred from the laser emitter, wherein the grinding part is configured to grind the first surface of the substrate, which has been introduced into the grinder, and the laser emitter is configured to emit the femtosecond pulse laser to the ground first surface of the substrate may be provided.