Planar Electron Emitter Tip with Work-Function-Lowering Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electron emitters, such as Schottky emitters, have limited throughput due to small emission areas and instability under high-brightness operation, which restricts their ability to achieve high beam current and resolution required for inspecting sub-100 nanometer IC components.
Innovation Solution
The development of electron emitters with a planar tip diameter of 0.05-10 micrometers coated with work-function-lowering materials like oxide, nitride, or oxynitride compounds, combined with a thermal field emission cathode and heating component, to enhance beam current and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the emission area of electron emitters is increased to achieve higher beam current, then the throughput is improved, but the brightness and resolution deteriorate due to the larger area reducing current density
Solution Approach 1:
The patent changes the geometric parameters of the emitter tip by creating a planar region with a specific diameter range (0.05-10 micrometers) instead of using conventional small-area tips. This parameter optimization allows the emitter to maintain high current density across a larger effective area, simultaneously improving throughput and brightness
Solution Approach 2:
The patent employs composite material structure by coating the emitter tip with work-function-lowering materials (such as oxide, nitride, or oxynitride compounds) on top of the base material. This composite structure reduces the work function of the emitter surface, enabling higher electron emission efficiency and brightness from the planar region without increasing the area
2Productivity
If the beam current is increased to improve throughput, then the inspection speed is improved, but the emission area becomes unstable and deforms under high temperature and electric field conditions
Solution Approach 1:
The patent applies preliminary protective measures by coating the emitter tip with work-function-lowering materials before operation. This coating forms a protective layer that stabilizes the emission area against deformation caused by high temperature and electric field during high-current operation, preventing instability before it occurs
Solution Approach 2:
The patent optimizes the physical and chemical parameters of the emitter surface by selecting specific work-function-lowering materials and controlling their thickness. This parameter optimization allows the emitter to operate at higher currents while maintaining emission area stability, as the modified surface properties resist thermal and electric field-induced deformation
3Measurement precision
If conventional small-area emitters are used to maintain high brightness, then the resolution is improved, but the maximum beam current is limited and throughput remains low
Solution Approach 1:
The patent fundamentally changes the emitter geometry parameter by introducing a planar region with diameter in the range of 0.05-10 micrometers, which is significantly larger than conventional small-area tips. This parameter change, combined with work-function-lowering coating, allows the emitter to deliver high beam current for improved throughput while maintaining sufficient current density for high resolution
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 solution enables higher brightness and beam current, improving the throughput of electron beam tools for inspecting IC components by maintaining a stable emission area and reducing surface deformation under high temperature and electric field conditions.
Implementation Method 1
a work-function-lowering material coated on the tip
Implementation Method 2
a heating component configured to provide thermal energy to the emitter
Implementation Method 3
a tip configured to release field emission electrons
Data Source
AI summary
Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.