Cathode Thermal Shielding for Low-Arc Multiply Charged Ion Generation
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Solution Overview
Problem
Current ion generation devices face challenges in generating a high number of multiply charged ions under low arc conditions, leading to increased abrasion and reduced productivity due to the need for high arc voltage and current, which shortens the device's lifespan and decreases semiconductor production efficiency.
Innovation Solution
The ion generation device incorporates a thermal shield around the cathode cap to narrow the emission range of thermoelectrons, combined with a repeller thermal shield to enhance plasma generation efficiency, allowing for the production of a larger number of multiply charged ions under lower arc conditions by promoting higher-density plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high arc voltage and current are used to generate multiply charged ions, then ion production efficiency is improved, but device lifespan deteriorates due to increased abrasion
Solution Approach 1:
The patent changes the physical parameters of the cathode cap (curvature radius, width, length ratios) to optimize thermoelectron emission characteristics. By adjusting these geometric parameters, the device achieves efficient ion production under lower arc conditions, reducing abrasion while maintaining productivity
Solution Approach 2:
The patent applies different geometric characteristics to different regions of the cathode cap. The curved tip portion has a specific curvature radius ratio (0.05-0.5 times the cathode cap width) to concentrate thermoelectron emission where needed, creating localized high-quality electron emission that improves ion generation efficiency without requiring high overall arc power
2Productivity
If high arc voltage and current are used to generate multiply charged ions, then ion production efficiency is improved, but maintenance frequency increases
Solution Approach 1:
The patent optimizes geometric parameters (curvature radius ratio between 0.05-0.5, width-to-length ratio between 0.2-0.8) to achieve sustainable operation conditions. These parameter adjustments enable the device to maintain high ion production efficiency while operating at lower arc power levels, significantly reducing maintenance frequency and improving ease of repair
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 enables the generation of higher-density plasma and extends the lifespan of the ion generation device, improving productivity by maintaining high ion production efficiency while reducing maintenance needs.
Implementation Method 1
a first cathode configured to supply a thermoelectron into the internal space, in which the first cathode includes a first cathode cap that protrudes in the axial direction toward an inside of the arc chamber and emits the thermoelectron supplied into the internal space, a first heat source that heats the first cathode cap
Implementation Method 2
a magnetic field generator that generates a magnetic field applied in an axial direction in the internal space
Implementation Method 3
an arc chamber including an internal space and including a front slit for extracting an ion beam from plasma generated in the internal space
Data Source
AI summary
An ion generation device includes an arc chamber including an internal space and including a front slit for extracting an ion beam from plasma generated in the internal space, a magnetic field generator that generates a magnetic field applied in an axial direction in the internal space, and a first cathode configured to supply a thermoelectron into the internal space. The first cathode includes a first cathode cap, a first heat source, and a first thermal shield including a first extension portion. A first tip portion, and a first tip opening, and a first opening width of the first tip opening in the radial direction is smaller than a maximum width of the first cathode cap in the radial direction.