Dual-Target Sputtering Layout for Dense Plasma Without Arcing
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Solution Overview
Problem
Conventional sputtering apparatuses face challenges in increasing plasma density without inducing abnormal discharges, limiting deposition rates.
Innovation Solution
A sputtering apparatus employing a configuration with first and second target holders, main magnetic field generation units, a radio-frequency electromagnetic field, and an auxiliary magnetic field to confine cations and electrons within the plasma generation region, while omitting magnetic fields at the ends of the target holders facing the radio-frequency electromagnetic field generation unit, promoting ionization and enhancing plasma density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If voltage is increased to increase plasma density, then plasma density increases, but abnormal discharge occurs
Solution Approach 1:
The patent replaces the conventional DC electric field generation method with a radio-frequency electromagnetic field generation unit. This substitution allows for more stable plasma generation at lower voltages, preventing abnormal discharge while maintaining high plasma density. The RF field enables controlled ionization without the breakdown issues associated with high-voltage DC systems.
Solution Approach 2:
The patent changes the frequency parameter of the electromagnetic field from DC to radio-frequency range. This parameter change fundamentally alters the plasma generation mechanism, allowing sustained plasma at lower voltages and preventing the abnormal discharge that occurs in conventional high-voltage DC sputtering systems.
2Quantity of substance
If auxiliary magnetic field is added at both ends to confine plasma, then plasma density increases, but interference with radio-frequency electromagnetic field occurs
Solution Approach 1:
The patent extracts or removes the auxiliary magnetic field generation means from the end of the target holder that faces the radio-frequency electromagnetic field generation unit. This selective removal eliminates the source of interference with the RF field while preserving the beneficial plasma confinement effects at other locations where the auxiliary magnetic field remains.
Solution Approach 2:
The patent applies different magnetic field configurations to different locations: auxiliary magnetic field generation means is provided at some ends of target holders but omitted at the specific end facing the RF unit. This local differentiation allows plasma confinement where needed while avoiding interference with RF field generation.
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 apparatus achieves increased plasma density and deposition rates by confining cations and electrons, preventing interference with the radio-frequency electromagnetic field, and optimizing magnetic field structures.
Implementation Method 1
a radio-frequency electromagnetic field generation unit configured to generate a radio-frequency electromagnetic field in the plasma generation region
Implementation Method 2
a first main magnetic field generation unit and a second main magnetic field generation unit respectively provided on a side of the first target opposite to the plasma generation region and on a side of the second target opposite to the plasma generation region, the first main magnetic field generation unit and the second main magnetic field generation unit being configured to generate a first main magnetic field and a second main magnetic field respectively on surfaces of the first target and the second target
Implementation Method 3
an auxiliary magnetic field generation unit configured to generate, at ends of the first target holder and the second target holder on the substrate holder side, an auxiliary magnetic field directed from one side to another side of the first target holder and the second target holder, the auxiliary magnetic field confining cations and electrons in the plasma generation region
Implementation Method 4
a power supply configured to generate an electric field in the plasma generation region by applying a predetermined potential to each of the first target holder and the second target holder
Implementation Method 5
a plasma source gas introduction unit configured to introduce a plasma source gas into the plasma generation region
Implementation Method 6
the auxiliary magnetic field confining cations and electrons in the plasma generation region
Implementation Method 7
a sputtering apparatus configured to form a film by sputtering a raw material of a target by plasma and depositing the material on a substrate
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
A sputtering apparatus (10) includes: a first target holder (111) and a second target holder (112) holding a first target (T1) and a second target (T2) respectively such that their surfaces face each other; a substrate holder (16) provided on a side of a plasma generation region (R) which is a region between the first target (T1) and the second target (T2) respectively held by the first target holder (111) and the second target holder (112); a first main magnetic field generation unit (121) and a second main magnetic field generation unit (122) respectively provided on the back surface sides of the first target holder (111) and the second target holder (112), and configured to generate a first main magnetic field and a second main magnetic field respectively on surfaces of the first target (T1) and the second target (T2) held, in which magnets are disposed such that opposite poles face each other; a power supply configured to generate an electric field in a plasma generation region (R) by applying predetermined potentials to the first target holder (111) and the second target holder (112); a radio-frequency electromagnetic field generation unit (17) configured to generate a radio-frequency electromagnetic field in the plasma generation region (R), which is provided on a side of the plasma generation region (R) facing the substrate holder (16) with the plasma generation region (R) between them; and a plasma source gas introduction unit (15) configured to introduce a plasma source gas into the plasma generation region (R), wherein means for generating a magnetic field does not exist at the ends of the first target holder (111) and the second target holder (112) on a side of radio-frequency electromagnetic field generation unit (17).