Electron Beam Blanking System Heat Distribution
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Solution Overview
Problem
Electron beam systems face issues with aperture diaphragm damage and dimensional errors due to high-power density during blanking, leading to pattern-stitching errors and reduced integration density in semiconductor manufacturing.
Innovation Solution
A heat-spreading blanking system using circular, square, or polygonal techniques with symmetric patterns to distribute heat evenly across the aperture diaphragm, reducing the risk of damage and enhancing throughput and resolution by maintaining the aperture's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher electron beam currents and energies are used to meet integration density requirements, then productivity and integration density are improved, but aperture diaphragm damage and pattern-stitching errors occur due to excessive heat concentration
Solution Approach 1:
The patent converts the harmful concentrated heat into a beneficial distributed heat pattern by deflecting the electron beam to trace a circular path around the aperture diaphragm during blanking. The heat that would normally concentrate at a single point is now distributed symmetrically around the entire aperture circumference, preventing damage while maintaining the ability to use high beam currents for improved productivity
2Speed
If the electron beam is deflected to a single position on the aperture diaphragm for blanking, then blanking speed is improved, but local heat concentration causes aperture distortion and pattern-stitching errors
Solution Approach 1:
The patent transitions from a one-dimensional point deflection to a two-dimensional circular path deflection around the aperture. By moving the beam along a circular trajectory in the aperture plane rather than to a single point, the heat is distributed around the entire aperture circumference, eliminating localized thermal distortion that causes pattern-stitching errors while maintaining fast blanking response
3Temperature
If the electron beam is scanned back and forth at any polar angle to reduce local heat, then heat distribution is improved, but the heat distribution remains rotationally asymmetrical causing edge rim shifting
Solution Approach 1:
The patent applies asymmetry in reverse by using symmetry to solve an asymmetry problem. The circular deflection path creates rotationally symmetrical heat distribution around the aperture, eliminating the rotational asymmetry that occurs with linear back-and-forth scanning. This symmetrical distribution prevents differential thermal expansion that would cause edge rim shifting and aperture positional instability
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 effectively reduces aperture damage and heat-related distortions, improving electron beam apparatus throughput and resolution, even with increased beam current or energy, by spreading heat symmetrically and maintaining dimensional stability.
Implementation Method 1
The high-density electron beam dissipates into a large amount of narrowly-distributed heat at the aperture diaphragm
Implementation Method 2
A kilowatt per square centimeter power density in a shaped electron beam apparatus can cause pattern-stitching errors of exposure due to the heat expansion effect of the aperture or aperture diaphragm
Implementation Method 3
Blanking systems typically deflect a high-power electron beam onto an aperture diaphragm
Data Source
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AI summary
An electron beam apparatus addresses blanking issues resulting from sinking high-power heat onto an aperture diaphragm by evenly spreading heat on the aperture diaphragm. The apparatus can include an aperture diaphragm and a deflector that deflects the electron beam on the aperture diaphragm. The electron beam is directed at the aperture diaphragm in a pattern around the aperture. The pattern may be a circle, square, or polygon. The pattern also may include a variable locus relative to the aperture.