Laser Ablation Mask Scanning for Uniform Large-Area Substrate Patterning
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Solution Overview
Problem
Current ablation processing technologies struggle to perform precise and uniform minute protrusions-and-recesses forming across large areas of semiconductor substrates due to reduced energy density and accuracy issues, particularly when dealing with high-aspect-ratio cylindrical features, leading to incomplete processing and defects.
Innovation Solution
A processing apparatus and method that uses a laser beam with a rectangular shape, shaped by a cylindrical lens system, and a mask with a pattern corresponding to the substrate area, where the substrate irradiation area is smaller than the processed area, allowing for sweep irradiation and synchronization of the mask and substrate stage to achieve uniform energy density and accurate processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a laser beam is used for ablation processing to form cylindrical VIAs and trenches, then high resolution and high energy density can be achieved, but the depth of focus is shallow making it difficult to process large-area substrates uniformly
Solution Approach 1:
The patent divides the processing area into multiple regions and processes them sequentially by moving the substrate stage. The laser beam processes one region at a time with high precision, then the stage moves to the next region, allowing large-area substrates to be processed uniformly despite the shallow depth of focus
Solution Approach 2:
The patent introduces dynamic movement of the substrate stage in the X and Y directions to expand the processable area. The stage moves continuously or in steps to bring different regions of the substrate into the laser processing zone, enabling large-area processing while maintaining the stationary high-precision laser beam
2Area of stationary object
If the substrate area to be processed is made large to meet high density requirements, then more features can be processed, but the energy density of the laser beam is reduced leading to incomplete processing
Solution Approach 1:
The patent segments the large substrate area into multiple smaller processing regions that can be handled sequentially. Each region receives concentrated laser energy at high density, ensuring complete processing, while the overall large area is covered through multiple sequential passes with stage movement
Solution Approach 2:
The patent maintains continuous useful action by coordinating the laser beam processing with continuous or stepped movement of the substrate stage. This allows the high-energy-density laser to process each point thoroughly while the system as a whole covers large areas through uninterrupted sequential processing
3Area of stationary object
If a scanning mechanism is used to move the laser beam across the substrate, then large areas can be processed, but processing accuracy deteriorates due to mechanical errors and thermal drift
Solution Approach 1:
Instead of moving the laser beam source (which causes accuracy deterioration), the patent inverts the approach by keeping the laser beam stationary and moving the substrate stage. This reversal eliminates the problems of mechanical scanning errors and thermal drift in the optical path, maintaining high processing accuracy while still enabling large-area processing through substrate movement
4Manufacturing precision
If multiple processing passes are performed to achieve deep features, then high-aspect-ratio cylindrical VIAs and trenches can be formed, but processing time increases significantly
Solution Approach 1:
The patent achieves continuous useful action by coordinating the laser processing with continuous substrate stage movement, eliminating idle time between passes. The system processes different regions continuously while forming deep features, reducing total processing time compared to stopping and starting at the same location multiple times
Solution Approach 2:
The patent uses dynamic substrate stage movement to optimize the multi-pass processing. By moving the stage continuously or in optimized steps between passes, the system minimizes non-productive time and maintains high utilization of the laser beam, reducing overall processing time while still achieving the required feature depth
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 high-precision, high-density, and efficient ablation processing across large substrate areas with reduced thermal drift and cost, allowing for accurate formation of deep VIA and trench features with improved processing speed and accuracy.
Implementation Method 1
a processing apparatus that forms minute protrusions and recesses on a surface of a substrate by ablation processing using irradiation energy of a laser beam
Implementation Method 2
a shaping optical system that shapes an irradiation shape of the laser beam from the laser light source into a rectangular shape
Data Source
AI summary
The present disclosure provides a processing apparatus that forms protrusions and recesses on a substrate surface by ablation processing using a laser beam.