Dual-Sided Sputter Etch of Patterned Hard Disks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasma etching technologies are inadequate for etching patterned hard disks, as they require etching on both sides and cannot apply clamping force or bias potential without a chuck, making existing systems unsuitable for hard disk fabrication.
Innovation Solution
A system utilizing a movable electrode to couple RF energy to both sides of the disk without applying chucking force, using capacitively or inductively coupled RF power and magnetic fields to sustain and shape the plasma, allowing for etching of both sides of the disk without a chuck, and employing a disk carrier to move between etch chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional plasma etching technology is used, then etching can be performed on one side of the substrate, but it cannot etch both sides of the hard disk
Solution Approach 1:
The system divides the etching process into two separate chambers, with each chamber equipped with its own plasma source and electrode assembly. This allows independent control and optimization of etching parameters for each side of the disk, enabling dual-sided etching while maintaining the effectiveness of conventional plasma etching technology
Solution Approach 2:
The invention transitions from a single-sided etching approach to a dual-sided etching approach by adding spatial dimensionality to the system. Two separate plasma sources are positioned on opposite sides of the disk, allowing simultaneous or sequential etching of both surfaces without interfering with each other
2Reliability
If a chuck is used to hold the disk, then bias potential can be applied to attract plasma species, but clamping force cannot be applied to the disk surface
Solution Approach 1:
The system introduces a non-contact intermediary mechanism where electric fields and plasma species serve as the medium to transfer energy and momentum to the disk surface. The plasma ions are accelerated by the bias potential toward the disk, providing the necessary bombardment without requiring mechanical contact or clamping force
Solution Approach 2:
The invention replaces the conventional mechanical chucking system with a plasma-based non-contact system. Instead of using mechanical clamping force to hold and position the disk, the system uses plasma confinement and electromagnetic fields to maintain the disk in position while applying bias potential for plasma species attraction
3Productivity
If plasma is sustained between the disk and electrode, then etching can be performed, but plasma may be sustainment between the disk and electrode which should be avoided
Solution Approach 1:
The system creates different plasma conditions in different regions: a dense plasma is maintained in the bulk etching zone between the electrode and disk surface to ensure high etch rates, while the gap region is kept plasma-free or with minimal plasma to prevent unwanted effects. This is achieved through carefully controlled electrode positioning, gas flow distribution, and power coupling parameters
Solution Approach 2:
The invention dynamically adjusts plasma-sustaining parameters such as RF power level, gas pressure, and electrode-to-disk gap distance to optimize the plasma distribution. By changing these parameters, the system maintains sufficient plasma density for high etch rates while preventing excessive plasma formation in regions where it would be harmful
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
Enables efficient etching of both sides of patterned hard disks, achieving high etch rates and overcoming the limitations of conventional systems by maintaining plasma between the disk and electrode, ensuring precise control and avoiding plasma sustainment between the disk and electrode.
Implementation Method 1
capacitively coupled RF power
Implementation Method 2
inductively coupled RF power
Implementation Method 3
sputter etch
Data Source
AI summary
A system is provided for etching patterned media disks. A movable electrode is utilized to perform sputter etch. The electrode moves to near or at slight contact to the substrate so as to couple RF energy to the disk. The material to be etched may be metal, e.g., Co/Pt/Cr or similar metals. The substrate is held vertically in a carrier and both sides are etched serially. That is, one side is etched in one chamber and then in the next chamber the second side is etched. An isolation valve is disposed between the two chambers and the disk carrier moves the disks between the chambers. The carrier may be a linear drive carrier, using, e.g., magnetized wheels and linear motors.