Laser Processing Shield with Purge Gas for Contamination Control
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Solution Overview
Problem
Thermal annealing processes in semiconductor manufacturing result in the volatilization of toxic elements and substrate ablation, leading to contamination within the annealing chamber and undesired redeposition on substrates and optics, necessitating an efficient method for removing byproducts during processing.
Innovation Solution
A laser processing system with a shield featuring an optically transparent window and gas inlets/outlets to introduce and remove purge gases, effectively removing volatilized components and maintaining a controlled atmosphere to prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal annealing is performed with high fluence laser, then annealing effectiveness is improved, but substrate ablation and contamination increase
Solution Approach 1:
The patent extracts and removes harmful volatized components and ablated material from the annealing chamber using a dedicated removal system with gas inlets and outlets. This allows high fluence annealing to proceed effectively while continuously extracting contaminants before they can cause damage or redeposition.
Solution Approach 2:
The patent introduces a controlled inert or reactive gas atmosphere into the annealing chamber to prevent unwanted chemical reactions and reduce contamination. The gas environment suppresses oxidation and other harmful reactions during high-fluence laser annealing while maintaining process effectiveness.
2Manufacturing precision
If thermal annealing is performed, then substrate properties are improved, but volatized toxic elements contaminate the chamber
Solution Approach 1:
The patent uses a pneumatic system with gas inlets and outlets to create controlled gas flow through the annealing chamber. This airflow actively transports volatized toxic elements away from the substrate and out of the chamber, preventing contamination while maintaining the thermal annealing process for substrate property improvement.
Solution Approach 2:
The patent extracts volatized toxic elements from the annealing chamber using a dedicated removal system. By continuously removing these harmful volatiles during the annealing process, the system maintains substrate property improvement without accumulating chamber contamination.
3Productivity
If high fluence laser annealing is used, then processing efficiency is improved, but redeposition on optics occurs
Solution Approach 1:
The patent extracts ablated material and volatized components before they can redeposit on optics by maintaining continuous gas flow through the chamber. This allows high-fluence laser annealing to proceed at high efficiency while preventing optics contamination that would otherwise require frequent cleaning or replacement.
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 system reduces contamination on substrates and system optics, ensuring consistent process uniformity and extending the time between cleaning or replacing optics, while maximizing device yield by effectively removing volatilized dopants and ablated material.
Implementation Method 1
The optically transparent window allows annealing energy to pass therethrough and to illuminate the substrate
Implementation Method 2
The purge gas is utilized to remove volatized or ablated components during thermal processing
Implementation Method 3
The transparent window has a coating thereon that is anti-reflective to radiation having a first wavelength
Implementation Method 4
The transparent window has a coating thereon that is reflective to radiation having a second wavelength
Data Source
AI summary
The present invention generally relates to a laser processing systems for thermally processing substrates. The laser processing systems include a shield disposed between an energy source of the laser processing system and a substrate which is to be thermally processed. The shield includes an optically transparent window disposed adjacent to a cavity within the shield. The optically transparent window allows annealing energy to pass therethrough and to illuminate the substrate. The shield also includes one or more gas inlets and one or more gas outlets for introducing and removing a purge gas from the cavity within the shield. The purge gas is utilized to remove volatized or ablated components during thermal processing, and to provide a gas of predetermined composition, such as oxygen-free, to the thermally processed area.