Charge Control Device for Multi-Beam Electron Alignment
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Solution Overview
Problem
The semiconductor manufacturing industry faces challenges in aligning and focusing multiple electron beams for inspection, particularly in multi-beam SEM systems, due to the complexity of generating and aligning these beams, which affects defect detection and yield in shrinking device dimensions.
Innovation Solution
A system comprising an electron source, relay lens, field lens, multi-pole array, projection lens, scintillator, fiber optics array, camera, and processor that generates and adjusts electron beams to minimize displacement, defocus, and aberration by using image data to apply voltage adjustments to the lenses and multi-pole array, with a feedback loop to maintain beam alignment and focus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple electron beams are generated for multi-beam SEM inspection, then productivity and inspection speed are improved, but device complexity and alignment difficulty increase
Solution Approach 1:
The patent divides a single electron beam into multiple separate beams using beam splitting optics. This segmentation allows parallel inspection of multiple areas simultaneously, improving productivity while the splitting mechanism itself manages the complexity of having multiple beams by generating them from a single source
Solution Approach 2:
The patent implements feedback control by detecting beam positions and adjusting beam alignment in real-time. Sensors monitor the positions of multiple electron beams, and control systems automatically adjust alignment parameters to maintain proper positioning, thereby reducing alignment complexity through active compensation
2Manufacturing precision
If multiple electron beams are used for inspection, then manufacturing precision and defect detection capability are improved, but beam alignment precision becomes more difficult to maintain
Solution Approach 1:
The system continuously monitors beam positions using detection optics and feedback control mechanisms. When beam positions drift from optimal alignment, the system automatically adjusts alignment parameters to restore precision, thereby maintaining beam alignment precision despite the complexity of managing multiple beams
Solution Approach 2:
The patent adjusts various parameters including lens currents, stigmator settings, and beam splitter configurations to optimize beam alignment. By dynamically changing these parameters based on detected beam positions, the system maintains high alignment precision across multiple beams
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 system effectively aligns and focuses electron beams, reducing defects and improving yield by minimizing displacement, defocus, and aberration, thereby enhancing the precision of semiconductor device inspection and manufacturing.
Implementation Method 1
The electron source generates electrons that form a plurality of electron beams
Implementation Method 2
A charge control device for a system with multiple electron beams includes a relay lens, a field lens, a multi-pole array, and a projection lens
Implementation Method 3
The scintillator is disposed downstream of the projection lens along a path of the electron beams
Implementation Method 4
The fiber optics array has a plurality of targets. The fiber optics array is disposed to receive light from each of the electrons beams using one of the targets
Data Source
AI summary
Systems and methods to focus and align multiple electron beams are disclosed. A camera produces image data of light from electron beams that is projected at a fiber optics array with multiple targets. An image processing module determines an adjustment to a voltage applied to a relay lens, a field lens, or a multi-pole array based on the image data. The adjustment minimizes at least one of a displacement, a defocus, or an aberration of one of the electron beams. Using a control module, the voltage is applied to the relay lens, the field lens, or the multi-pole array.