Planar Field Emission Cathode Array for Uniform Electron Emission
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Solution Overview
Problem
The three-dimensional structure of field emission cathode arrays with varying cone heights and diameters leads to poor uniformity, causing local over-emission and space discharge, resulting in device damage and reliability issues.
Innovation Solution
A field emission cathode electron source and array design where the cathode, cathode tip, and gate are disposed on the same plane, with the electron emission end directed parallel to the substrate, facilitating easier control of fabrication parameters and avoiding electric arcs through substrate isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a three-dimensional field emission pointed cone array structure is used, then high-density integration and high total emission current can be achieved, but the uniformity of the array deteriorates due to variations in cone height and diameter
Solution Approach 1:
The patent transitions from a three-dimensional cone structure to a planar two-dimensional structure where the cathode, cathode tip, and gate are disposed on the same plane. This dimensional reduction eliminates the height variation problem inherent in 3D cones while maintaining high emission current through optimized planar geometry and close proximity of components.
2Productivity
If the distance between the micro pointed cone and the gate is reduced, then electron emission efficiency is improved, but the risk of space discharge and electric arcs increases
Solution Approach 1:
The patent introduces a gate structure that acts as an intermediary control element between the cathode and the emission region. By applying gate voltage, the electric field is precisely controlled, enabling high emission current density while preventing uncontrolled space discharge and electric arcs through active field management.
3Productivity
If the radius of curvature of the micro emission pointed cone is reduced, then electron emission is enhanced, but fabrication difficulty increases and uniformity deteriorates
Solution Approach 1:
The patent replaces the curved three-dimensional cone surface with a planar two-dimensional structure featuring a cathode tip with controlled geometry. This eliminates the difficulty of fabricating and controlling small radius of curvature cones while achieving enhanced emission through optimized planar tip geometry and electric field configuration.
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 design enhances the stability and uniformity of the field emission cathode array, reducing the risk of electric arcs and improving the reliability of associated devices by simplifying the fabrication process and optimizing cathode tip structure.
Implementation Method 1
reducing the height of the barrier and narrowing the width of the barrier, so that a considerable number of electrons travel from the inside of the field emitting material to the outside thereof through the tunneling effect
Implementation Method 2
The field emission electron source suppresses the surface barrier of a field emitting material by applying a strong electric field outside the field emitting, material, reducing the height of the barrier and narrowing the width of the barrier
Data Source
AI summary
A field emission cathode electron source and an array thereof provided by embodiments of the present disclosure include a substrate, and a cathode, a cathode tip and a gate disposed on the same side of the substrate. The cathode, the cathode tip and the gate are disposed on an upper surface of the substrate, and the cathode tip is connected to the cathode, and the gate is located on a side of the cathode tip away from the cathode and an electron emission end of the cathode tip is directed toward a side of the substrate close to the gate. The cathode tips are arranged on the substrate in parallel with the substrate. Compared with the three dimensional stacked structure in the prior art, the present disclosure has a higher stability and reliability and is suitable for a large-scale integration.