Charged Particle Gun Alignment Assembly with Double Stage Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High brightness charged particle beam systems face complex alignment challenges due to reduced virtual source size, leading to increased beam inclination and misalignment with the optical axis, which complicates the alignment process and affects the precision of micrometer and nanometer scale inspection and structuring tasks.
Innovation Solution
A charged particle beam device with a gun alignment assembly that includes a condenser lens, a final beam limiting aperture, and a double-stage deflection assembly positioned between the condenser lens and the final aperture, where the working distance of the condenser lens is 15 mm or less, to compensate for misalignment and improve beam alignment accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the virtual source size is reduced to improve brightness, then the brightness of the charged particle source is improved, but the alignment complexity increases due to increased beam inclination and misalignment with the optical axis
Solution Approach 1:
The alignment system is segmented into multiple independent stages: a first alignment stage positioned between the condenser lens and final beam limiting aperture, and a second alignment stage positioned between the final beam limiting aperture and the objective lens. This segmentation allows each stage to handle specific alignment tasks independently, reducing the overall alignment complexity while maintaining high brightness performance
Solution Approach 2:
The patent introduces a new spatial dimension for alignment by positioning alignment stages at different locations along the optical path (between condenser lens and aperture, and between aperture and objective lens). This multi-dimensional approach to alignment allows complex beam inclination corrections to be broken down into manageable stages, each operating in a specific spatial region
2Illumination intensity
If the virtual source size is reduced to improve brightness, then the brightness of the charged particle source is improved, but the alignment precision becomes more difficult to achieve
Solution Approach 1:
The first alignment stage performs preliminary alignment of the charged particle beam before it passes through the final beam limiting aperture. This preliminary action corrects beam inclination and positioning errors early in the optical path, making it easier to achieve the required alignment precision for high brightness operation
Solution Approach 2:
The patent employs alignment sensors that detect the position and inclination of the charged particle beam and provide feedback to the alignment stages. This feedback mechanism enables precise adjustment of the beam path, ensuring that alignment precision requirements are met while maintaining high brightness performance
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 enables more effective and accurate alignment of charged particle beams, enhancing the precision of micrometer and nanometer scale inspection and structuring tasks while maintaining a compact alignment system, effectively addressing the complexity of high brightness beam alignment.
Implementation Method 1
a condenser lens for imaging the virtual source, wherein the working distance of the condenser lens is 15 mm or less
Implementation Method 2
a double stage deflection assembly positioned between the condenser lens and the final beam limiting aperture
Data Source
AI summary
A charged particle gun alignment assembly for emitting a charged particle beam along an optical axis of a charged particle beam device is described. The charged particle gun alignment assembly is configured to compensate for misalignment of the charged particle beam and includes a charged particle source having an emitter with a virtual source defining a virtual source plane substantially perpendicular to the optical axis; a condenser lens for imaging the virtual source; a final beam limiting aperture adapted for shaping the charged particle beam; and a double stage deflection assembly positioned between the condenser lens and the final beam limiting aperture, wherein the working distance of the condenser lens is 15 mm or less.