Magnetron Plasma Source Layout for Ultra-High Vacuum Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in achieving highly efficient discharge processes in ultra-high vacuum states, particularly in small micro electro mechanical systems (MEMS) vacuum pumps and magnetron sputtering methods, which struggle to maintain plasma confinement and efficiency at vacuum levels below 10−5 Pa.
Innovation Solution
A plasma source configuration involving specific magnet arrangements and electrode placements, including first and second magnets with opposing magnetic poles, surrounded by third and fourth magnets, with defined magnetic field strength ratios and electrode potentials, to create a magnetron and parallel magnetic field for efficient plasma confinement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a small MEMS vacuum pump structure is used, then the device size is reduced, but the discharge efficiency deteriorates in ultra-high vacuum state
Solution Approach 1:
The device is divided into two functional sections: a plasma generation section with cathode and anode electrodes for ion generation, and a pumping section with getter material for gas absorption. This segmentation allows each section to optimize its function independently, maintaining high discharge efficiency in a compact form factor.
Solution Approach 2:
The plasma generation function and vacuum pumping function are merged into a single integrated device. The plasma source generates ions that are directly directed onto the getter material within the same device, combining ionization and gas absorption processes to achieve efficient ultra-high vacuum pumping in a small volume.
2Device complexity
If conventional plasma source configuration is used, then the structure is simple, but plasma confinement efficiency deteriorates
Solution Approach 1:
Magnetic fields are applied locally in specific regions to confine plasma. The magnetic field is concentrated where needed (between electrodes and around the plasma source) rather than uniformly distributed, improving plasma confinement efficiency while minimizing overall device complexity.
Solution Approach 2:
Magnetic fields are introduced as a third dimension (spatial confinement) to control plasma behavior, in addition to the electrical fields from electrodes. This adds a new degree of freedom for plasma confinement without fundamentally redesigning the electrode structure.
3Manufacturing precision
If magnetron sputtering method is used, then film formation capability is improved, but discharge efficiency deteriorates in ultra-high vacuum state
Solution Approach 1:
The essential film formation capability is extracted and replaced with a getter material that directly absorbs gas molecules. Instead of using complex magnetron sputtering processes for vacuum pumping, the patent extracts the core function of gas removal and implements it through simple getter material absorption, achieving better discharge efficiency.
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 proposed configuration enables high-density plasma generation and efficient discharge in ultra-high vacuum states, improving plasma generation efficiency up to 10−6 Pa, suitable for applications like ion pumps and small cooled atomic clocks.
Implementation Method 1
a first magnet, a second magnet arranged so that a second magnetic pole different from a first magnetic pole faces the first magnetic pole of the first magnet, a third magnet having the second magnetic pole different from the first magnetic pole directed in the same direction as the first magnetic pole of the first magnet and arranged to surround the first magnet, and a fourth magnet having the first magnetic pole different from the second magnetic pole facing the second magnetic pole of the third magnet and arranged to surround the second magnet
Implementation Method 2
a first electrode provided on sides of the first magnetic pole of the first magnet and the second magnetic pole of the third magnet, a second electrode facing the first electrode and provided on sides of the second magnetic pole of the second magnet and the first magnetic pole of the fourth magnet, and a third electrode arranged between the first electrode and the second electrode so that a voltage having a higher potential than those of the first electrode and the second electrode is applied thereto
Data Source
AI summary
A small plasma source that enables highly efficient discharge in an ultra-high vacuum state includes a first magnet, a second magnet arranged so that a second magnetic pole faces the first magnetic pole of the first magnet, a third magnet having the second magnetic pole directed in the same direction as the first magnetic pole of the first magnet and arranged to surround the first magnet, a fourth magnet having the first magnetic pole different from the second magnetic pole facing the second magnetic pole of the third magnet and arranged to surround the second magnet, a first electrode provided on sides of the first magnetic pole of the first magnet and the second magnetic pole of the third magnet, a second electrode facing the first electrode and provided on sides of the second magnetic pole of the second magnet and the first magnetic pole of the fourth magnet, and a third electrode arranged between the first electrode and the second electrode. A value obtained by dividing a shorter distance between a distance between the first magnet and the second magnet and a distance between the third magnet and the fourth magnet by an average value of thicknesses of the first to fourth magnets is 1 or more and 10 or less.