EUV Light Source Droplet Control via Electrostatic Ejection
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Solution Overview
Problem
Current extreme ultraviolet (EUV) light source apparatuses face challenges in generating high-quality EUV light for advanced semiconductor microfabrication, particularly at sub-32 nm scales, due to inefficiencies in droplet formation and debris management during the plasma generation process.
Innovation Solution
The apparatus employs a target output device with a nozzle unit, electrode unit, voltage control unit, pressure control unit, and output control unit to generate and control droplets of target material, using electrostatic force and pressure synergy to produce high-speed, small-sized droplets that are precisely outputted and synchronized with laser irradiation, minimizing debris and optimizing EUV light production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional EUV light source apparatuses are used, then EUV light can be generated, but droplet formation efficiency is low and debris is generated during plasma generation
Solution Approach 1:
The patent replaces conventional mechanical or thermal droplet formation methods with electrostatic field-based droplet ejection. The voltage control unit applies electrostatic force to pull target material through the nozzle unit, forming droplets without mechanical contact or thermal processing, thereby reducing debris generation while improving droplet formation efficiency
Solution Approach 2:
The patent changes the physical state and properties of target material delivery by controlling voltage and pressure parameters. The voltage control unit adjusts electrostatic force strength, while the pressure control unit regulates pressure on target material, enabling precise control of droplet size, speed, and formation timing to optimize EUV light production and minimize debris
2Productivity
If larger droplets are used for plasma generation, then plasma can be formed, but EUV light production efficiency decreases and debris increases
Solution Approach 1:
The patent uses voltage and pressure parameter control to precisely regulate droplet size. By adjusting the electrostatic force strength and pressure applied to target material, the system produces small-sized droplets that are optimal for EUV light generation, avoiding the debris and inefficiency associated with larger droplets
Solution Approach 2:
The patent replaces conventional droplet size control methods with electrostatic field-based manipulation. The electrostatic force selectively pulls target material through the nozzle to form uniformly small droplets, eliminating the need for mechanical size reduction processes that generate debris
3Manufacturing precision
If target material is outputted without precise timing control, then material delivery is simple, but synchronization with laser irradiation is poor and EUV light quality decreases
Solution Approach 1:
The patent implements feedback control through the output control unit, which receives timing signals and adjusts voltage and pressure control accordingly. The system monitors and synchronizes droplet ejection timing with laser irradiation timing, ensuring precise coordination for optimal EUV light generation while maintaining controlled complexity through automated feedback loops
Solution Approach 2:
The patent applies preliminary action by pre-controlling voltage and pressure conditions before droplet ejection. The output control unit prepares the electrostatic field and pressure state in advance, ensuring that droplets are formed and ejected at precisely the right moment to synchronize with laser irradiation, improving precision without requiring complex real-time adjustments
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 enables efficient generation of high-speed, small-sized droplets that enhance EUV light production efficiency, reduce debris, and improve the precision and quality of microfabrication processes, meeting the demands of next-generation semiconductor technology.
Implementation Method 1
a voltage control unit that applies predetermined voltage between the electrode unit and the target material to generate electrostatic force therebetween for pulling out the target material through the nozzle unit
Implementation Method 2
a pressure control unit that applies predetermined pressure to the target material
Implementation Method 3
An extreme ultraviolet light source apparatus for generating extreme ultraviolet light by irradiating a target with a laser beam
Implementation Method 4
generating extreme ultraviolet light by irradiating a target with a laser beam
Data Source
AI summary
A target output device may include: a main body for storing a target material; a nozzle unit, connected to the main body, for outputting the target material as a target; an electrode unit provided so as to face the nozzle unit; a voltage control unit that applies predetermined voltage between the electrode unit and the target material to generate electrostatic force therebetween for pulling out the target material through the nozzle unit; a pressure control unit that applies predetermined pressure to the target material; and an output control unit that causes the target to be outputted through the nozzle unit by controlling signal output timing of each of a first timing signal and a second timing signal, the first timing signal causing the voltage control unit to apply the predetermined voltage between the target material and the electrode unit at first timing, and the second timing signal causing the pressure control unit to apply the predetermined pressure to the target material at second timing.