Toroidal Sputtering Target for Uniform Erosion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sputtering targets experience non-uniform wear and erosion due to magnetic fields, leading to significant material waste, as only about 30% of the target material is consumed before reaching the end of its useful life, with existing solutions requiring adjustments to the sputtering device or additional steps to maximize material utilization.
Innovation Solution
A sputtering target configuration featuring a toroidal portion extending from a planar substrate plate, designed to receive the magnetic field and evenly distribute the bombardment of high-energy ions, allowing for uniform erosion and extending the target's useful life without requiring modifications to the sputtering device or additional steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a conventional planar disc target is used, then the sputtering device operates with a simple structure, but the magnetic field causes non-uniform erosion and significant material waste (only 30% consumption)
Solution Approach 1:
The patent applies curvature by transitioning from a flat planar disc to a toroidal (doughnut-shaped) target geometry. This curved configuration redistributes the magnetic field lines and ion bombardment patterns across the target surface, converting the concentrated racetrack erosion into uniform erosion across the entire toroidal surface, thereby achieving over 95% material utilization without requiring complex external magnetic field adjustments
2Loss of substance
If helical magnets or yoke magnets are used to achieve uniform magnetic field, then material utilization improves to 90%, but the sputtering device requires modifications
Solution Approach 1:
The toroidal target geometry inherently creates locally optimized conditions for uniform erosion. The curved surfaces and varying radial distances from the magnetic field source automatically adjust the local magnetic field intensity and ion bombardment distribution, eliminating the need for complex helical or yoke magnet configurations while achieving superior material utilization
Solution Approach 2:
The toroidal target structure self-regulates the magnetic field distribution and erosion pattern through its geometry alone. The shape itself serves to distribute the magnetic field uniformly without requiring additional magnetic components or device modifications, making the system self-sufficient in achieving uniform erosion
3Duration of action of stationary object
If the racetrack portion is refilled with more material, then the target can be reused, but additional processing steps are required
Solution Approach 1:
The toroidal target geometry is pre-configured to ensure uniform erosion from the beginning of its operational life. By designing the target shape to inherently distribute erosion uniformly, the need for subsequent refilling or reprocessing steps is eliminated, extending the target's useful life through its entire material inventory without additional manufacturing interventions
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 toroidal sputtering target achieves greater than 95% material consumption during its useful life, reducing waste and maximizing target material utilization by ensuring uniform erosion, while maintaining the high-purity and expensive nature of the target materials.
Implementation Method 1
The electric field accelerates the ionized gas atoms 202 toward the target 204
Implementation Method 2
the gas atoms 202 are ionized via their collision with electrons 210 accelerated away from the surface of the cathode 208
Implementation Method 3
The toroidal portion extending from a top surface of the substrate plate reduces non-uniform erosion against the plate caused by a magnetic field during the sputtering process
Implementation Method 4
The target 204 is subjected to bombardment by the high energy ions to dislodge and eject material 214 from the target 204
Implementation Method 5
Sputtering, also referred to as 'sputter coating' is a process in which thin films are deposited from a solid sputtering target onto a substrate
Data Source
AI summary
A sputtering target having a unitary body. The unitary body includes a planar substrate plate and a toroidal portion extending from a top surface of the substrate plate. The toroidal portion reduces non-uniform erosion against the plate caused by a magnetic field applied to the target. In use, the magnetic field is initially received at the toroidal portion. After the magnetic field wears down the toroidal portion, the magnetic field is received at the substrate plate.