Rotating Bias Magnetic Field for Uniform Target Wear in Sputtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the magnetic material sputtering process, the uneven plasma density distribution caused by the superposition effects of the bias magnetic field and the target surface magnetic field leads to uneven target recessed depths, resulting in reduced target life, low utilization, and non-uniform magnetic film deposition.
Innovation Solution
A bias magnetic field control method that rotates the bias magnetic field device by a fixed angle along the circumferential direction of the base at predetermined consumption times to periodically change the area of the target surface affected by the bias magnetic field, preventing excessive recessed depths and uniformity issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a bias magnetic field device is used to form a horizontal magnetic field for aligning magnetic domains, then in-plane anisotropic magnetic film is formed, but uneven plasma density distribution occurs due to superposition effects with target surface magnetic field
Solution Approach 1:
The bias magnetic field device is rotated at predetermined intervals during the sputtering process, transforming the static magnetic field application into a dynamic one. This rotation changes the area of the target surface affected by the bias magnetic field over time, preventing localized plasma density anomalies and extending target life while maintaining in-plane anisotropic magnetic film formation.
2Manufacturing precision
If bias magnetic field is applied continuously to align magnetic domains, then magnetic film anisotropy is achieved, but target recessed depth becomes uneven leading to reduced target life
Solution Approach 1:
The bias magnetic field device rotates periodically during the sputtering process, applying the magnetic field to different areas of the target surface at different times. This periodic action prevents continuous erosion at the same location, distributing the wear evenly across the target surface and significantly extending target life while maintaining magnetic domain alignment.
3Productivity
If bias magnetic field is applied to increase sputtering rate, then deposition efficiency improves, but target surface wear becomes non-uniform causing film thickness non-uniformity
Solution Approach 1:
By rotating the bias magnetic field device during sputtering, the area of high sputtering rate is dynamically shifted across different regions of the target surface. This prevents localized rapid wear while maintaining overall high deposition efficiency, ensuring uniform film thickness across substrates processed on the same target.
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 method extends the target life, improves utilization, and ensures uniform film thickness, reducing manufacturing costs by maintaining even target surface wear and consistent deposition.
Implementation Method 1
A bias magnetic field device may be configured to form a horizontal magnetic field in a deposition chamber so that when the magnetic material is sputtered and deposited, the magnetic domain of the magnetic material is aligned in the horizontal direction
Implementation Method 2
when the magnetic material is sputtered and deposited
Data Source
AI summary
A bias magnetic field control method includes: in response to a consumption time length of a material of a target reaching a first preset time length of consuming the material of the target, rotating a bias magnetic field device by a fixed angle along a circumferential direction of a base, and repeatedly rotating the bias magnetic field device after every first preset time length of consuming the material of the target, to periodically change an area, where a bias magnetic field is applied to, of a surface of the target until a total time length of consuming the material of the target accumulates to reach an upper limit. Each time, the bias magnetic field device is rotated in a same direction and each time, a number of substrates is deposited by the material of the target.