EUV Light Generation via Dual-Pulse Laser Targeting
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Solution Overview
Problem
Current EUV light generation systems for semiconductor production face challenges in achieving high conversion efficiency and minimizing debris generation when producing feature sizes below 32 nm, particularly in generating EUV light with a wavelength of approximately 13 nm for advanced microfabrication processes.
Innovation Solution
The system employs a laser beam apparatus to generate a pre-pulse and a main pulse laser beam, where the target material is irradiated with a pre-pulse laser beam to create a diffused target, which is then irradiated with a main pulse laser beam within a specific time frame to optimize plasma generation and EUV light production, utilizing various laser beam configurations and polarization control to enhance energy absorption and reduce debris.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single pulse laser beam is used to irradiate the target material, then the process is simple, but the conversion efficiency of EUV light generation is insufficient
Solution Approach 1:
The laser beam is divided into two distinct pulses: a pre-pulse (first laser beam) and a main pulse (second laser beam). The pre-pulse irradiates the target material first to create a modified surface state, followed by the main pulse which generates EUV light more efficiently. This segmentation of the single pulse into multiple pulses resolves the contradiction by maintaining process simplicity while significantly improving conversion efficiency.
Solution Approach 2:
The pre-pulse laser beam performs preliminary action on the target material by irradiating it before the main pulse. This preliminary irradiation modifies the target surface state, creating conditions that enhance the subsequent EUV light generation. The pre-pulse prepares the target in advance, allowing the main pulse to achieve higher conversion efficiency without complicating the overall process.
2Ease of operation
If laser beam parameters are not optimized, then the system operation is simple, but debris generation is excessive
Solution Approach 1:
The system optimizes specific parameters of the laser beams including pulse duration, energy, and temporal interval between the pre-pulse and main pulse. By carefully controlling these parameters, the system achieves effective debris suppression while maintaining ease of operation. The parameter optimization creates ideal conditions for EUV generation that minimize harmful debris without requiring complex operational procedures.
Solution Approach 2:
The system incorporates control mechanisms that monitor and adjust laser beam parameters based on the desired outcome. By implementing feedback control over the pre-pulse and main pulse characteristics, the system can suppress debris generation effectively while keeping the operation simple through automated parameter management rather than manual complexity.
3Device complexity
If the target material is not pre-treated, then the process is straightforward, but energy absorption efficiency is low
Solution Approach 1:
The pre-pulse laser beam performs preliminary treatment on the target material before the main pulse arrives. This preliminary action modifies the target surface properties, creating a state that enhances energy absorption during the main pulse irradiation. The pre-treatment is integrated into the laser processing sequence itself, adding minimal complexity while dramatically improving energy absorption efficiency.
Solution Approach 2:
The system uses periodic pulsed laser action with a specific temporal structure: a pre-pulse followed by a main pulse after a controlled interval. This periodic action with optimized timing allows the target material to respond optimally to each pulse, maximizing energy absorption during the main pulse while keeping the process relatively simple through automated pulse sequencing.
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 approach significantly improves the conversion efficiency of EUV light generation while minimizing debris, enabling the production of smaller feature sizes by efficiently absorbing the main pulse laser energy and controlling the diffusion process to achieve high-temperature, high-density plasma.
Implementation Method 1
irradiating the target material with a pre-pulse laser beam from the laser beam apparatus
Implementation Method 2
create a diffused target
Implementation Method 3
irradiating the target material having been irradiated with the pre-pulse laser beam with a main pulse laser beam
Implementation Method 4
efficiently absorbing the main pulse laser energy and controlling the diffusion process to achieve high-temperature, high-density plasma
Implementation Method 5
generating extreme ultraviolet light
Implementation Method 6
achieve high-temperature, high-density plasma
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.