Rectangular Magnet Unit With Third Magnet For Sputtering
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Solution Overview
Problem
The existing sputtering apparatuses using magnetron cathodes face challenges in achieving a high target utilization rate due to insufficient leakage magnetic flux density when the width of the magnet unit is reduced, leading to inefficient utilization of the target material.
Innovation Solution
A sputtering apparatus with a magnet unit configuration that includes a first and second magnet magnetized perpendicular to the target surface, and a third magnet positioned between them in the short-side direction, magnetized in the short-side direction to enhance leakage magnetic flux density, ensuring efficient target utilization even with a reduced magnet unit width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the width of the magnet unit is reduced, then the target utilization rate is improved, but the leakage magnetic flux density becomes insufficient
Solution Approach 1:
The magnet unit employs magnets with different magnetization directions in different regions. The first and second magnets are magnetized in the thickness direction to provide baseline magnetic field, while the third magnet is magnetized in the width direction to locally enhance leakage magnetic flux density at critical positions, thereby maintaining reliable magnetic field strength even when the overall magnet unit width is reduced.
Solution Approach 2:
The magnet unit uses an asymmetric configuration where the third magnet is positioned specifically between the first and second magnets in the width direction. This asymmetric arrangement creates concentrated leakage magnetic flux in specific regions, improving the magnetic field effectiveness without requiring a proportional increase in the overall magnet unit width.
2Area of stationary object
If a rectangular magnet unit is swung, then the erosion region is expanded, but the end portions of the target are not efficiently utilized
Solution Approach 1:
The invention changes the magnetic field distribution parameters by introducing the third magnet with different magnetization direction and position. This creates a more uniform and extended erosion pattern across the target surface, including the end portions, thereby improving overall target utilization rate while maintaining an expanded erosion region through swinging motion.
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 configuration increases leakage magnetic flux density on the target surface, improving the target utilization rate by expanding the erosion region and maintaining sufficient magnetic field strength, thus extending the target's lifespan and usage efficiency.
Implementation Method 1
a magnet unit of a rectangular shape having a long side and a short side, which is configured to apply a magnetic field
Implementation Method 2
a first magnet magnetized in a direction perpendicular to the target mounting surface; a second magnet disposed around the first magnet and magnetized in the direction perpendicular to the target mounting surface
Implementation Method 3
a sputtering apparatus including: a target holder having a target mounting surface
Data Source
AI summary
A sputtering apparatus comprises: a target holder; and a magnet unit of a rectangular shape having long and short sides. The magnet unit includes: a first magnet; a second magnet disposed surrounding the first magnet and magnetized in a different and opposite direction from a direction of magnetization of the first magnet, and a third magnet located at part between the first magnet and the second magnet in the short-side direction and at least at a center position between the first magnet and the second magnet, the third magnet being magnetized in the short-side direction. In the third magnet, a surface facing the second magnet has the same polarity as that of a surface of the second magnet on the target holder side, and a surface facing the first magnet has the same polarity as that of a surface of the first magnet on the target holder side.