EUV Droplet Acceleration via Segmented Gas Flow
Solution Overview
Problem
In extreme ultraviolet (EUV) light generation for semiconductor manufacturing, existing systems face challenges in maintaining the integrity and spacing of droplets during plasma generation, leading to issues like uncombined droplets and reduced EUV light efficiency due to the proximity of droplets and the impact of gas flow on droplet velocity and direction.
Innovation Solution
The introduction of a gas flow generation device with a specific gas outlet configuration along the droplet trajectory, combined with a vibrating element to generate smaller droplets that combine into a final droplet, ensures stable acceleration and increased spacing between droplets, preventing uncombined droplets and enhancing EUV light generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If gas flow is applied to accelerate droplets, then droplet velocity increases, but droplet trajectory stability deteriorates
Solution Approach 1:
The gas flow is segmented into multiple outlets arranged along the droplet trajectory. Each gas outlet provides localized acceleration at different positions, preventing single-point disturbance that would destabilize the droplet trajectory while achieving cumulative velocity increase.
Solution Approach 2:
The gas flow acts as an intermediary between the droplet generator and the plasma generation region, providing controlled acceleration without direct mechanical contact. The gas molecules transfer momentum to droplets gradually through multiple interaction points, maintaining trajectory stability.
2Productivity
If droplets are supplied in close proximity to increase plasma generation efficiency, then EUV light output increases, but droplet combination reliability deteriorates
Solution Approach 1:
Droplets are pre-accelerated by gas flow before reaching the plasma generation region, ensuring they maintain proper spacing and timing. This preliminary acceleration prevents droplet clustering and ensures reliable individual droplet formation at the target location, even when supplied in close proximity.
Solution Approach 2:
The system dynamically adjusts droplet spacing and acceleration timing based on real-time conditions. By making the droplet supply and acceleration process dynamic rather than static, the system maintains optimal spacing for reliable combination while maximizing EUV light output through increased supply frequency.
3Manufacturing precision
If multiple small droplets are combined to form a larger droplet, then droplet size control improves, but the risk of uncombined droplets increases
Solution Approach 1:
The combination process is segmented into multiple controlled stages with gas flow assistance at each stage. Gas outlets positioned along the trajectory provide localized acceleration that ensures small droplets merge completely before reaching the plasma region, preventing uncombined droplets from reaching the target.
Solution Approach 2:
The system incorporates feedback mechanisms to monitor droplet combination status and adjust gas flow and droplet supply parameters in real-time. This feedback control ensures that droplets are properly combined while maintaining the precision of final droplet size, reducing the risk of uncombined droplets.
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 configuration effectively accelerates the final droplet without disturbing the minute droplets, increasing the distance between them and reducing defects like uncombined droplets, thereby improving the consistency and efficiency of EUV light generation for semiconductor manufacturing.
Implementation Method 1
a vibrating element configured to generate, by applying vibration to a nozzle through which the target substance is output, a plurality of second droplets
Implementation Method 2
a gas flow generation device having a gas outlet for causing gas to flow along a travel direction of the first droplet around at least a part of a trajectory of the first droplet
Implementation Method 3
a laser produced plasma (LPP) type apparatus using plasma generated by irradiating a target substance with laser light
Implementation Method 4
irradiating a target substance with laser light has been developed
Data Source
AI summary
An extreme ultraviolet light generation apparatus may include a chamber; a droplet generator configured to sequentially supply a first droplet of target substance to a plasma generation region in the chamber; and a gas flow generation device having a gas outlet for causing gas to flow along a travel direction of the first droplet around at least a part of a trajectory of the first droplet. Here, the droplet generator includes a vibrating element configured to generate, by applying vibration to a nozzle through which the target substance is output, a plurality of second droplets each having smaller volume than the first droplet and to cause the second droplets to be combined to generate the first droplet, and the gas outlet is located downstream, on a trajectory direction of the first droplet, of a position where the second droplets are combined and the first droplet is generated.