Multi-Electrode Charged Particle Extraction Device for Low-Emittance Ion Beams
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Solution Overview
Problem
Current methods for extracting high brightness ion beams from plasmas, such as Liquid Metal Ion Source technology, face challenges in achieving brightness exceeding 10^5 A/sr/m^2 due to unwanted doping effects and difficulties in designing electrodes that minimize emittance growth and aberrations.
Innovation Solution
A multi-stage electrode system is designed with specific aperture shapes and potential distributions to create a low-emittance beam, ensuring zero or near-zero electric fields at the apertures of the last electrodes, which compensates for space charge forces and minimizes beam aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If Liquid Metal Ion Source technology is used to extract high brightness ion beams, then beam brightness exceeds 10^5 A/sr/m^2, but unwanted doping effects are introduced into the substrate
Solution Approach 1:
The invention changes the composition parameters of the ion beam by using inert gas plasma (e.g., argon, neon, helium) instead of liquid metal sources, thereby maintaining high brightness while eliminating gallium doping effects. The plasma parameters including electron temperature, ion density, and potential distribution are optimized to achieve the required beam quality without contamination.
2Manufacturing precision
If electrode extraction systems are designed to minimize emittance growth, then beam quality improves, but achieving brightness in excess of 10^5 A/sr/m^2 remains difficult
Solution Approach 1:
The invention applies different potential distributions to different regions of the extraction system. The plasma potential is optimized locally at the extraction aperture to minimize emittance growth, while the overall system maintains high brightness through localized field configurations. The electrode shapes and potentials are specifically designed to create favorable local conditions for both beam quality and brightness.
Solution Approach 2:
The invention employs dynamic optimization of the plasma potential distribution and electrode configurations to simultaneously achieve low emittance growth and high brightness. The system allows for adjustable parameters including plasma density, electron temperature, and extraction field strength to be tuned for optimal performance.
3Quantity of substance
If strong electric fields are applied to extract ions from plasma, then ion beam intensity increases, but emittance growth and aberrations increase
Solution Approach 1:
The invention segments the extraction process into multiple stages with distributed potential drops across several electrodes rather than a single strong field. This multi-electrode configuration allows the total extraction voltage to be divided into manageable segments, reducing the strength of individual electric fields while maintaining high ion beam intensity through cumulative acceleration.
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 solution achieves high brightness ion beams with low emittance growth, enabling focused beams suitable for submicron feature creation in applications like semiconductor fabrication without introducing doping effects, and can produce beams with brightnesses greater than 10^5 A/sr/m^2.
Implementation Method 1
The shapes of the electrodes and the potentials applied to them produce a low-emittance beam
Implementation Method 2
The shapes and potentials applied to the electrodes produce a substantially zero electric field in the vicinity of the aperture of the last electrode furthest from the particle source
Data Source
AI summary
The present invention provides a method for extracting a charged particle beam from a charged particle source. A set of electrodes is provided at the output of the source. The potentials applied to the electrodes produce a low-emittance growth beam with substantially zero electric field at the output of the electrodes.