Atom Probe with Curved Reflectron Electrodes
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Solution Overview
Problem
Conventional three-dimensional atom probes face limitations in analyzing poorly conducting or insulating materials due to energy uncertainty and limited mass resolution, particularly when dealing with similar masses in varying abundances, and suffer from chromatic aberration and narrow fields of view.
Innovation Solution
Incorporating a sub-nanosecond laser for ion evaporation and a wide-angle reflectron with curved electrodes to perform time focusing and reduce chromatic aberration, enabling higher mass resolution and wider field of view analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage pulsing is used for ion evaporation, then ionization and acceleration of atoms occurs, but energy uncertainty and limited mass resolution result
Solution Approach 1:
The patent replaces the conventional voltage pulsing mechanism with a laser-based evaporation system. The laser provides controlled energy delivery to evaporate ions from the specimen surface, eliminating the energy uncertainty associated with voltage pulses while maintaining effective ionization and acceleration.
Solution Approach 2:
The patent changes the fundamental parameter for ion evaporation from electrical voltage pulses to laser energy parameters (wavelength, pulse duration, intensity). This parameter change enables precise control of the evaporation process and improves mass resolution by eliminating the energy spread inherent in voltage pulsing methods.
2Measurement precision
If conventional reflectron is used, then time focusing is achieved, but chromatic aberration and narrow field of view persist
Solution Approach 1:
The patent employs curved electrode surfaces in the reflectron design rather than flat surfaces. The curved geometry enables wider angular acceptance of ion trajectories while maintaining the time focusing effect, thereby expanding the field of view without sacrificing mass resolution.
Solution Approach 2:
The patent introduces additional spatial dimensions to the reflectron design through curved electrodes arranged in a three-dimensional configuration. This allows ions from a wider range of angles to be focused in time, effectively expanding the field of view while maintaining chromatic aberration correction.
3Adaptability or versatility
If voltage pulse is applied to highly conductive specimen, then ion evaporation occurs, but poorly conducting or insulating materials cannot be analyzed
Solution Approach 1:
The patent replaces the electrical voltage pulsing system with an optical laser system for ion evaporation. Since lasers interact with materials through optical absorption rather than electrical conduction, this enables analysis of poorly conducting and insulating materials that cannot be analyzed with conventional voltage pulsing methods.
Solution Approach 2:
The patent changes the interaction mechanism from electrical (voltage pulses requiring high conductivity) to optical (laser absorption). By selecting appropriate laser wavelengths and pulse parameters, the system can effectively evaporate ions from a wide range of materials including semiconductors, oxides, and insulators.
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 combination achieves improved mass resolution and wider field of view analysis, reducing energy variations and chromatic aberration, allowing for more precise elemental identification and spatial imaging of specimens like semiconductors and oxides.
Implementation Method 1
a sub-nanosecond laser to evaporate ions from a specimen
Implementation Method 2
a reflectron for reflecting the ions. The reflectron can include a front electrode and a back electrode. At least one of the front and back electrodes can be capable of generating a curved electric field
Implementation Method 3
calculates the mass/charge ratio of the resulting ion by measuring the time-of-flight (TOF) of the ion from the specimen to the detector
Data Source
AI summary
Aspects of the present invention are directed generally toward atom probe and three-dimensional atom probe microscopes. For example, certain aspects of the invention are directed -toward an atom probe or a three-dimensional atom probe that includes a sub-nanosecond laser to evaporate ions from a specimen under analysis and a reflectron for reflecting the ions. In further aspects of the invention, the reflectron can include a front electrode and a back electrode. At least one of the front and back electrodes can be capable of generating a curved electric field. Additionally, the front electrode and back electrodes can be configured to perform time focusing and resolve an image of a specimen.