Laser Edge Shaping for Wide-Bandgap Wafers With Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional edge shaping methods for semiconductor wafers, particularly those made of wide bandgap materials like silicon carbide, are inefficient and costly due to the use of consumable tools that incur material loss, time inefficiencies, and environmental waste, while lacking effective feedback mechanisms for achieving desired edge profiles.
Innovation Solution
A laser-based system is employed to ablate the edge portions of semiconductor wafers, allowing for precise edge shaping without consumable tools, using non-surface contacting technologies that reduce material loss and operational costs, and incorporating sensors and controllers for active feedback to ensure accurate alignment and parameter achievement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional edge shaping methods using consumable tools are used, then edge shaping can be achieved, but material loss increases and manufacturing cost increases
Solution Approach 1:
The patent replaces mechanical consumable tools with a laser-based ablation system. The laser beam directly ablates the semiconductor wafer edge through photothermal decomposition, eliminating the need for mechanical contact and consumable grinding wheels. This substitution resolves the contradiction by achieving precise edge profiles through controlled material removal via laser energy without the material loss associated with mechanical tool wear and chip generation.
Solution Approach 2:
The patent employs programmable laser parameters (power, pulse duration, scanning speed, wavelength) to control the ablation process. By dynamically adjusting these parameters, the system achieves precise edge profiles while minimizing material removal to only what is necessary for shaping. This parameter control resolves the contradiction by enabling accurate edge formation with minimal waste compared to fixed-parameter mechanical processes.
2Manufacturing precision
If conventional edge shaping methods are used, then edge shaping can be performed, but processing time increases and productivity decreases
Solution Approach 1:
The laser ablation process operates continuously as the laser beam scans along the wafer periphery, removing material in a single uninterrupted pass. This continuous action eliminates the intermittent tool changes, wheel dressing, and setup adjustments required by conventional mechanical methods. The result is both high precision edge profiles and improved productivity, resolving the contradiction between manufacturing precision and processing speed.
3Manufacturing precision
If conventional edge shaping methods are used, then processing can be completed, but setup complexity increases and test wafer requirements increase
Solution Approach 1:
The patent incorporates feedback mechanisms including real-time monitoring of ablation depth, laser power stabilization, and automated focus control. This feedback enables the system to self-correct and maintain precise edge profiles without requiring multiple test wafers for parameter optimization. The reduced setup complexity and elimination of extensive test wafer usage resolve the contradiction while maintaining high manufacturing precision.
4Loss of substance
If conventional edge shaping methods are used, then material removal can be achieved, but environmental waste increases
Solution Approach 1:
By replacing mechanical grinding with laser ablation, the patent eliminates the generation of large volumes of abrasive slurry, coolant waste, and spent grinding wheels that characterize conventional methods. The laser process produces minimal waste in the form of vaporized material that can be evacuated and filtered. This substitution resolves the contradiction by achieving efficient material removal while dramatically reducing environmental waste.
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 laser-based edge shaping method reduces material waste, lowers manufacturing costs, and enhances setup efficiency by providing precise edge profiles with minimal material loss and reduced need for test wafers, while ensuring consistent quality through real-time feedback.
Implementation Method 1
ablating the edge portion of the wide bandgap semiconductor workpiece with the laser to remove material from the edge portion of the wide bandgap semiconductor workpiece
Data Source
AI summary
Systems and methods for laser-based processing of semiconductor wafers are provided. In one example, a method includes providing emission of a laser from a laser source towards an edge portion of a wide bandgap semiconductor workpiece from a direction facing a side surface of the wide bandgap semiconductor workpiece, the side surface extending between a first major surface of the wide bandgap semiconductor workpiece and an opposing second major surface of the wide bandgap semiconductor workpiece. The method includes ablating the edge portion of the wide bandgap semiconductor workpiece with the laser to remove material from the edge portion of the wide bandgap semiconductor workpiece.