Arc Evaporation Source Slanted Magnet Arc Spot Control
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Solution Overview
Problem
Existing arc evaporation sources for ceramic hard film formation inefficiently utilize cathode material, as arc spots tend to move away from the center of the discharge surface, leading to incomplete utilization of the cathode material, especially as the number of film formation batches increases.
Innovation Solution
The arc evaporation source employs a magnetic field configuration with magnetic lines forming an acute angle with respect to the substrate direction at the outer circumference and perpendicular to the discharge surface, utilizing a slanted permanent magnet and a rotating or displacement apparatus to maintain arc spots within the discharge area, optimizing the magnetic field orientation between 20° to 45° with respect to the discharge surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a permanent magnet is disposed at a back side of the cathode with magnetic poles oriented along the axis direction, then arc spots are prevented from escaping out of the discharge surface, but the discharge area is mainly concentrated near the outer circumference such that the cathode material is not able to be effectively used up to the center portion
Solution Approach 1:
The invention changes the orientation parameter of the permanent magnet from axial (parallel to cathode axis) to slanted (at a specific angle relative to the cathode axis). This parameter change transforms the magnetic field distribution, causing magnetic lines to form an acute angle with the substrate direction at the outer circumferential surface and be substantially perpendicular at the outermost circumference, thereby redistributing the discharge area more uniformly across the cathode surface including the center portion.
2Reliability
If a tapered confinement ring is disposed at the outer circumference of the cathode to prevent arc spots from escaping, then arc spot containment is improved, but the outer circumference of the discharge surface is not able to be used to the fullest
Solution Approach 1:
The invention replaces the geometric constraint approach (tapered confinement ring) with a field-based approach (slanted permanent magnet). By changing the magnetic field orientation parameter, arc spots are contained without physical obstruction, allowing the entire discharge surface including the outer circumference to be fully utilized for material evaporation.
3Reliability
If the discharge area is concentrated near the outer circumference, then arc spots are contained on the discharge surface, but the volume of cathode material utilized is reduced as represented by V2=V1×(D2÷D1) where D2>D1
Solution Approach 1:
The invention changes the magnetic field orientation parameter to distribute the discharge area more uniformly across the entire cathode surface. This parameter change increases the effective diameter D2 in the volume utilization formula V2=V1×(D2÷D1), thereby increasing the volume of cathode material that can be utilized while maintaining arc spot stability through the slanted magnetic 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 configuration significantly increases the utilization efficiency of the cathode material by maintaining arc spots within the discharge area, allowing for more effective use of the cathode material across a larger surface area and extending the lifespan of the cathode.
Implementation Method 1
a magnetic field generating apparatus disposed at a back side of the cathode, wherein the magnetic field generating apparatus generates a magnetic field which forms magnetic lines that form an acute angle with respect to a substrate direction at an outer circumferential surface of the cathode
Implementation Method 2
an arc evaporation source for melting and evaporating a cathode material by arc discharge in a vacuum for film formation on a surface of a substrate
Implementation Method 3
melting and evaporating a cathode material by arc discharge
Data Source
AI summary
Provided is an arc evaporation source for melting and evaporating a cathode material by arc discharge for film formation on a surface of a substrate, and including a cathode formed in a substantially disc shape and a magnetic field generating apparatus, disposed at a back side of the cathode. The magnetic field generating apparatus generates a magnetic field which forms magnetic lines that form an acute angle with respect to a substrate direction at an outer circumferential surface of the cathode, magnetic lines that are substantially perpendicular to the discharge surface at an outermost circumference part of the discharge surface of the cathode, and magnetic lines that form an acute angle with respect to a center direction of the cathode at a region towards the outer circumferential surface of the discharge surface of the cathode, by at least one permanent magnet disposed at the back side of the cathode.