Non-Shot-Noise Electron Source for High Throughput Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electron sources for lithography and inspection are limited by shot noise, which restricts the signal-to-noise ratio and throughput of electron beam systems, making it difficult to achieve high data rates and improve lithographic quality and inspection efficiency.
Innovation Solution
An electron source design that avoids beam apertures at non-focal planes, maintaining electron correlation and focusing the beam only at focal planes to achieve a signal-to-noise ratio below the shot noise limit, thereby increasing throughput and reducing noise content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If beam apertures are positioned at non-focal planes in conventional electron sources, then beam shaping and current control are achieved, but shot noise limits the signal-to-noise ratio and reduces throughput
Solution Approach 1:
The patent removes beam apertures from non-focal planes, extracting the noise-generating element from the system. By eliminating apertures at intermediate planes and only retaining apertures at focal planes where they serve a constructive purpose, the system achieves signal-to-noise ratios below the conventional shot noise limit while maintaining high throughput
Solution Approach 2:
The patent changes the spatial parameter of aperture positioning from arbitrary non-focal planes to specifically focal planes only. This parameter change transforms the electron beam propagation characteristics, preserving electron correlation and achieving non-shot-noise-limited performance with enhanced signal-to-noise ratio and throughput
2Quantity of substance
If conventional electron sources are used, then beam current is controlled through apertures, but electron correlation is lost and noise content increases
Solution Approach 1:
The patent uses focal planes as intermediary regions where apertures can selectively filter electrons without destroying correlation. By positioning apertures only at focal planes where electron trajectories converge, the system maintains electron correlation while still achieving current control, thereby reducing noise content while preserving beam intensity
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 enhances the signal-to-noise ratio and throughput of electron beam systems, allowing for higher data rates and improved lithographic quality and inspection efficiency by utilizing a non-shot-noise limited electron source.
Implementation Method 1
A cathode is configured to emit electrons
Implementation Method 2
A cathode is configured to emit electrons
Implementation Method 3
an anode is configured to accelerate the electrons so as to create an electron beam
Implementation Method 4
An electron lens may be configured to focus the electron beam to form a cathode image at a focal plane
Implementation Method 5
An electron lens may be configured to focus the electron beam to form a cathode image at a focal plane
Data Source
AI summary
One embodiment relates to an electron source apparatus for an electron beam lithography tool or an electron beam inspection tool. A cathode is configured to emit electrons, and an anode is configured to accelerate the electrons so as to create an electron beam. There are no beam apertures in the electron source apparatus that are positioned at non-focal planes. An electron lens may be configured to focus the electron beam to form a cathode image at a focal plane, and a beam aperture may positioned at the focal plane. Other embodiments, aspects and features are also disclosed.