Quadrupole Magnetic Energy Filter for Ion Beam Contamination
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Solution Overview
Problem
Conventional ion implantation systems face challenges in reducing particle contamination, particularly in low-energy beamlines, where the proximity of the workpiece to the ion source increases the risk of contamination, affecting the quality of semiconductor devices.
Innovation Solution
A quadrapole magnetic energy filter is positioned downstream of the decelerator and upstream of the workpiece in the ion implantation system to filter out neutral ions and contaminants from the ion beam, improving beam coherence and reducing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the beamline is kept short to provide high current and reduce beam blow-up, then beam current and beam coherence are improved, but particle contamination increases due to closer proximity between ion source and workpiece
Solution Approach 1:
A magnetic energy filter is introduced as an intermediary component between the decelerator and the workpiece. This filter selectively transmits ions of specific energies while blocking contaminants, thereby mediating the interaction between the ion beam and workpiece to reduce contamination without sacrificing beam current
Solution Approach 2:
The beamline is segmented into distinct functional zones: an acceleration section, a deceleration section, and a filtered implantation section. The magnetic energy filter creates a separate functional zone that selectively processes different particle types, allowing high current transmission while blocking contaminants
2Object-affected harmful factors
If a magnetic energy filter is added downstream of the decelerator to reduce contamination, then particle contamination is reduced, but device complexity increases
Solution Approach 1:
The magnetic energy filter serves multiple functions simultaneously: it acts as an energy selector for ions, a spatial filter for contaminants, and a beam quality enhancer. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in system complexity
Solution Approach 2:
The magnetic energy filter combines energy selection and spatial filtering functions into a single integrated component. By merging these functions, the system avoids the complexity of having separate energy selectors and contaminant filters
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 magnetic energy filter effectively minimizes particle contamination, enhances beam coherence, and allows for a longer beamline, reducing the risk of contamination and improving the optical quality of the ion beam for semiconductor processing.
Implementation Method 1
a magnetic energy filter positioned downstream of the decelerator and upstream of the workpiece in an ion implantation system
Implementation Method 2
quadrapole magnetic energy filter is configured to further filter neutral ions from the ion beam
Data Source
AI summary
A system and method for magnetically filtering an ion beam during an ion implantation into a workpiece is provided, wherein ions are emitted from an ion source and accelerated the ions away from the ion source to form an ion beam. The ion beam is mass analyzed by a mass analyzer, wherein ions are selected. The ion beam is then decelerated via a decelerator once the ion beam is mass-analyzed, and the ion beam is further magnetically filtered the ion beam downstream of the deceleration. The magnetic filtering is provided by a quadrapole magnetic energy filter, wherein a magnetic field is formed for intercepting the ions in the ion beam exiting the decelerator to selectively filter undesirable ions and fast neutrals.