Wafer Laser Dicing Using Self-Condensing Beam Focusing
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Solution Overview
Problem
Current wafer dicing processes face challenges in achieving high precision and yield due to errors caused by focusing lens optical systems and height sensors, which can lead to uneven laser beam concentration and reduced semiconductor device quality.
Innovation Solution
A wafer processing apparatus that uses a laser source to generate pulses with a self-condensing phenomenon, concentrating the laser beam inside the wafer without a focusing lens optical system or height sensor, allowing for precise internal cracking and dicing through a collimated beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a focusing lens optical system is used to concentrate the laser beam inside the wafer, then the laser beam can be focused to achieve dicing, but errors occur due to height sensor measurements and focusing inaccuracies leading to uneven laser beam concentration
Solution Approach 1:
The patent removes the focusing lens optical system and height sensor from the laser dicing apparatus. By extracting these components that introduce measurement and focusing errors, the system achieves more reliable and consistent laser beam concentration inside the wafer without the sources of error that these components create.
Solution Approach 2:
The laser beam itself is used to create the focusing effect through self-focusing in the wafer material. Instead of relying on external focusing lenses and height sensors to determine the focus position, the system allows the laser beam to self-organize and concentrate at the desired depth within the wafer through controlled propagation, eliminating the need for complex focusing optics and height measurement systems.
2Ease of operation
If a focusing lens optical system with height sensor is used, then laser beam focusing is possible, but errors are introduced leading to reduced semiconductor device quality
Solution Approach 1:
The patent extracts and removes the focusing lens optical system and height sensor from the apparatus. This elimination of error-prone components directly improves semiconductor device quality by preventing the introduction of focusing and measurement errors that would otherwise degrade manufacturing precision.
Solution Approach 2:
The patent replaces the mechanical and optical focusing system (lenses and height sensors) with a purely optical self-focusing mechanism. The laser beam's own properties and interaction with the wafer material create the necessary focusing effect, substituting complex mechanical-optical systems with a simpler optical phenomenon-based approach.
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 method improves the yield of semiconductor devices by ensuring accurate and consistent laser beam concentration within the wafer, eliminating errors associated with traditional focusing systems and enhancing the precision of the dicing process.
Implementation Method 1
parameters of the laser source are set such that the laser beam is collected inside the wafer by a self-condensing phenomenon while inside of the wafer
Implementation Method 2
the wafer is cut by irradiating, onto the workpiece, laser light in a wavelength band with a high absorption rate and heating and melting the workpiece
Data Source
AI summary
Provided is a wafer processing apparatus including a laser source for generating a laser beam including a plurality of pulses, a wafer support configured to support a wafer, and a beam transmission optical system for transferring the laser beam output from the laser source to the wafer, wherein the laser source sets parameters of the laser beam so that the laser beam is collected inside the wafer by a self-condensing phenomenon while moving along the inside of the wafer.