Unbalanced Magnetron with RF Electrode for Plasma Ionization
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Solution Overview
Problem
Existing ionized physical vapor deposition (I-PVD) sputtering technologies face limitations in achieving high-density plasma generation and efficient target material deposition, particularly in unbalanced magnetron configurations, which affect the ionization and deposition processes.
Innovation Solution
The implementation of an electrically and magnetically enhanced unbalanced magnetron sputtering apparatus with an unbalanced magnetic field configuration, an additional electrode isolated from ground, and a power supply generating bipolar or RF voltage to enhance plasma ionization and deposition efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If an unbalanced magnetron configuration is used, then magnetic field lines are concentrated at the edges, but plasma density and ionization efficiency are insufficient
Solution Approach 1:
The patent combines an unbalanced magnetron sputtering source with an inductively coupled plasma (ICP) source in a single apparatus. The ICP coil generates a separate plasma region that enhances the overall plasma density and ionization efficiency, compensating for the limitations of the unbalanced magnetron configuration while maintaining its edge-concentrated magnetic field characteristics.
2Shape
If magnetic field lines are unbalanced from the center, then edge concentration is improved, but deposition uniformity across the substrate deteriorates
Solution Approach 1:
By merging the unbalanced magnetron source with an ICP source, the patent creates a hybrid system where the ICP plasma provides additional ionization that compensates for the non-uniform magnetic field distribution. This allows the magnetic field to maintain its edge-concentrated configuration for high ionization efficiency while the ICP component ensures more uniform plasma distribution across the substrate for improved deposition uniformity.
Solution Approach 2:
The patent applies RF power to the ICP coil, creating a controllable plasma source that can be independently adjusted. By changing the RF power parameters and gas flow rates, the system can optimize the balance between edge-concentrated magnetic field effects and overall plasma uniformity, achieving both high ionization efficiency and acceptable deposition uniformity.
3Power
If additional electrode assemblies are added, then plasma generation is enhanced, but device complexity increases
Solution Approach 1:
The additional electrode assembly serving as an ICP coil is designed to perform multiple functions: generating plasma through inductive coupling, enhancing ionization of sputtered material, and providing a controllable power input mechanism. This multi-functional design enhances plasma generation capability while minimizing the increase in device complexity by consolidating functions into a single integrated component.
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 approach increases the ionization of sputtered target material atoms, improves plasma density, and enhances the deposition process by controlling electron density and ion energy, leading to more effective layer formation on substrates.
Implementation Method 1
Magnetic field geometry of the electrically and magnetically enhanced unbalanced magnetron sputtering source has an unbalanced magnetron configuration on a cathode target surface. Magnetic field lines that form a magnetron configuration on the cathode target surface are unbalanced from the center.
Implementation Method 2
The additional electrode is connected to a power supply that can generate a positive, negative or high frequency bipolar voltage with a frequency in the range of 100 KHz to 100 MHz. In some embodiments, the additional electrode is connected to the power supply that generates an RF voltage.
Implementation Method 3
An ionized physical vapor deposition (I-PVD) sputtering and resputtering process can be performed in the same process module. The I-PVD sputtering source is a magnetron sputtering source, in which magnetic field lines terminate on a target surface.
Implementation Method 4
The gap cathode can be grounded through an inductor to eliminate negative voltage bias generated by RF discharge.
Implementation Method 5
The disclosed embodiments relate to an apparatus and method of generating high density capacitive coupled plasma (CCP) for sputtering applications
Data Source
AI summary
An electrically and magnetically enhanced ionized physical vapor deposition (I-PVD) magnetron apparatus and method is provided for sputtering material from a cathode target on a substrate, and in particular, for sputtering ceramic and diamond-like coatings. The electrically and magnetically enhanced magnetron sputtering source has unbalanced magnetic fields that couple the cathode target and additional electrode together. The additional electrode is electrically isolated from ground and connected to a power supply that can generate positive, negative, or bipolar high frequency voltages, and is preferably a radio frequency (RF) power supply. RF discharge near the additional electrode increases plasma density and a degree of ionization of sputtered material atoms.