Laser-Produced Plasma EUV Light Generation with Segmented Pulse Control
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in generating extreme ultraviolet (EUV) light with sufficient intensity and efficiency for microfabrication features below 32 nm, particularly in achieving high conversion efficiency and minimizing debris generation.
Innovation Solution
A system and method involving a laser-produced plasma (LPP) type EUV light generation system that uses a driver laser to irradiate a target material with a pre-pulse and main pulse laser beam, controlling beam intensity and timing to create a diffused target, which is then excited to produce EUV light, optimizing the shape and timing of the diffused target to enhance energy absorption and plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a single high-intensity laser pulse is used to generate EUV light, then the EUV light intensity can be sufficient, but the conversion efficiency is low and debris generation is high
Solution Approach 1:
The single high-intensity laser pulse is segmented into multiple lower-intensity pulses (pre-pulse, main pulse, and optional additional pulses) separated by time intervals. This segmentation allows the target material to be processed in stages: the pre-pulse creates a diffused target structure, and the main pulse generates EUV light from this optimized target, thereby improving conversion efficiency while maintaining sufficient EUV intensity.
Solution Approach 2:
A pre-pulse laser beam is applied before the main EUV-generating pulse to pre-process the target material. This preliminary action creates a diffused target with optimized density and spatial distribution, which then more efficiently converts the main pulse energy into EUV radiation, reducing energy loss and improving overall conversion efficiency.
2Illumination intensity
If a single high-intensity laser pulse is used to generate EUV light, then the EUV light intensity can be sufficient, but debris generation is high
Solution Approach 1:
The laser pulse is segmented into multiple pulses with different intensities and timing. The pre-pulse creates a diffused target structure that reduces debris generation, while the main pulse generates EUV light from this optimized target. This segmented approach maintains sufficient EUV intensity while significantly reducing debris compared to a single high-intensity pulse.
Solution Approach 2:
The pre-pulse performs preliminary processing of the target material to create an optimized diffused target structure before the main EUV-generating pulse arrives. This preliminary structuring of the target reduces the formation of debris during the main pulse interaction, thereby reducing harmful debris generation while maintaining EUV light intensity.
3Productivity
If the laser beam intensity is increased to improve EUV generation, then the EUV light output increases, but the target material is damaged more rapidly
Solution Approach 1:
The laser pulse is segmented into multiple pulses with optimized intensity distribution. The pre-pulse uses lower intensity to create the diffused target structure, and the main pulse uses higher intensity for EUV generation. This segmentation allows the target material to withstand repeated irradiation cycles, extending its operational lifetime while maintaining high EUV light output.
Solution Approach 2:
The laser irradiation is applied periodically with multiple pulses separated by time intervals that allow the target material to partially recover between pulses. This periodic action with optimized pulse timing maintains high EUV light output over extended periods while reducing cumulative damage to the target material, thereby extending its lifetime.
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 achieves high conversion efficiency and reduces debris generation, enabling effective EUV light production suitable for next-generation semiconductor manufacturing, particularly for feature sizes below 32 nm.
Implementation Method 1
a laser beam apparatus configured to generate a laser beam to be introduced into the chamber
Implementation Method 2
a Laser Produced Plasma (LPP) type system in which plasma is generated by irradiating a target material with a laser beam
Implementation Method 3
The target material may be irradiated with the laser beam for generating extreme ultraviolet light
Data Source
AI summary
A system includes a chamber, a laser beam apparatus configured to generate a laser beam to be introduced into the chamber, a laser controller for the laser beam apparatus to control at least a beam intensity and an output timing of the laser beam, and a target supply unit configured to supply a target material into the chamber, the target material being irradiated with the laser beam for generating extreme ultraviolet light.