Focused Ion Beam Apparatus with Electric Field Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Focused ion beam apparatuses with gas field ion sources face challenges in achieving stable beam irradiation due to complex structures and susceptibility to vibrations, which complicates accurate adjustment and leads to beam instability.
Innovation Solution
The apparatus incorporates a gas field ion gun unit with an emitter tip, a gas supply unit, an extracting electrode, a cathode electrode, an aperture to restrict the ion beam, and a lens system arranged on the sample side to focus the beam, allowing only central ions to pass through, thereby reducing aberration and stabilizing the beam without complex mechanical adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a complex adjusting mechanism is used to accurately adjust the tip direction, then the ion beam extraction accuracy is improved, but the device complexity and cost increase
Solution Approach 1:
The patent replaces the complex mechanical adjusting mechanism with an electric field-based alignment system. Alignment electrodes generate electric fields that deflect the ion beam to achieve accurate positioning without mechanical movement of the tip, thereby reducing device complexity while maintaining extraction accuracy.
Solution Approach 2:
The patent introduces alignment electrodes as an intermediary element between the ion source and the sample. These electrodes mediate the ion beam direction through electric field deflection, eliminating the need for direct mechanical adjustment of the tip and simplifying the overall system structure.
2Measurement precision
If a complex adjusting mechanism is used to accurately adjust the tip direction, then the ion beam extraction accuracy is improved, but the stability against vibrations deteriorates
Solution Approach 1:
By replacing mechanical adjustment mechanisms with electric field-based alignment, the system eliminates mechanical moving parts that are susceptible to vibrations. The electric field alignment remains stable under vibrational conditions, improving beam reliability while maintaining extraction accuracy.
3Quantity of substance
If the full ion beam is allowed to pass through the lens system, then the beam current is maximized, but the beam profile quality deteriorates due to peripheral component mixing
Solution Approach 1:
The patent applies local quality by selectively allowing only central portion ions to pass through the lens system while blocking peripheral ions. This creates a quality gradient where the central beam region provides high-quality focused ions for precise work, while peripheral ions are filtered out to prevent beam profile degradation.
4Manufacturing precision
If the aperture is positioned before the lens system, then the beam profile is improved by filtering peripheral ions, but the ion beam current is reduced
Solution Approach 1:
The aperture is strategically positioned to filter only the peripheral portion of the ion beam while allowing the central, high-quality ions to pass through to the lens system. This selective filtering improves beam profile quality without excessively reducing the useful ion beam current.
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 stable and focused ion beam irradiation with reduced aberration and beam current variations, improving the beam profile and resistance to external vibrations, thus eliminating the need for costly and complex adjustment mechanisms.
Implementation Method 1
an extracting electrode configured to ionize the gas adsorbed onto the surface of the tip and extract ions by applying a voltage between the extracting electrode and the tip
Implementation Method 2
a cathode electrode configured to accelerate the ions toward a sample
Implementation Method 3
a lens system configured to focus the ion beam onto the sample
Data Source
AI summary
A focused ion beam apparatus includes an ion gun unit having an emitter tip, a gas supply unit that supplies gas to the tip, and an ion source gas supply source. An extracting electrode ionizes the gas adsorbed onto the surface of the tip and extracts ions by applying a voltage between the extracting electrode and the tip. A cathode electrode accelerates the ions toward a sample. An aperture member has an opening that passes therethrough a part of the ion beam ejected from the ion gun unit, and a lens system focuses the ion beam onto the sample.