Plasma Processing Apparatus Waveguide Phase Control
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Solution Overview
Problem
Conventional plasma processing apparatuses using μ waves face challenges in achieving uniform and stable plasma generation due to nonuniformity in electric field distribution and eigen modes caused by plasma density variations, leading to difficulties in introducing circularly polarized waves effectively.
Innovation Solution
A plasma processing apparatus is designed with a hollow resonator chamber, a tuning box for merging and controlling μ-waves, and multiple rectangular waveguides forming specific angles and phase differences to control electric field phases, along with a reflection control chamber to manage reflective waves, allowing for the rotation of the electric field in a wide range of plasma densities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a μ wave is used for plasma generation, then high-density plasma can be achieved, but the plasma becomes nonuniform in the radial and circumferential directions due to eigen modes
Solution Approach 1:
The invention divides the single μ-wave source into multiple (three or more) waveguides that introduce waves from different directions into the processing chamber. This segmentation allows the superposition of multiple wave fields to create a more uniform plasma distribution while maintaining high density, effectively resolving the eigen mode nonuniformity problem.
Solution Approach 2:
The invention introduces waves with different phases and directions at different locations around the processing chamber. By controlling the phase and direction of each waveguide individually, the plasma properties are optimized locally in different regions, achieving overall uniformity while maintaining high density throughout the chamber.
2Manufacturing precision
If conventional antenna methods are used to solve nonuniformity, then some uniformity improvement may be achieved, but electric-field distributions of near fields and eigen modes cannot be eliminated
Solution Approach 1:
Instead of using complex single-antenna structures with multiple elements, the invention segments the wave introduction into multiple simple waveguides. Each waveguide is a straightforward component, but their collective arrangement and phase control achieve the desired uniformity while eliminating near-field and eigen-mode effects.
Solution Approach 2:
The invention transitions from conventional single-direction or planar wave introduction to three-dimensional multi-directional wave injection. By introducing waves from multiple directions simultaneously with controlled phases, the system achieves uniform plasma distribution without the complexity of elaborate antenna designs.
3Manufacturing precision
If circularly polarized wave converter with stubs is used, then circumferential nonuniformity can be eliminated, but the structure becomes complex and dielectric loss occurs
Solution Approach 1:
The invention replaces the complex circularly polarized wave converter with multiple simple waveguides arranged in specific configurations. Each waveguide introduces linearly polarized waves that, when superimposed with controlled phases, achieve the same circumferential uniformity effect without requiring complex stub structures or dielectric materials.
Solution Approach 2:
The invention extracts and eliminates the complex circularly polarized wave converter component entirely, replacing it with a simpler multi-waveguide system. This removes the source of dielectric loss and structural complexity while maintaining the desired uniformity through alternative means of wave superposition.
4Quantity of substance
If multiple waveguides with phase control are used, then plasma uniformity and density can be improved, but the device complexity increases
Solution Approach 1:
The invention uses multiple independent waveguides that can be controlled individually. Each waveguide is a standard, well-understood component, and their collective control through phase adjustment achieves high-density uniform plasma without requiring fundamentally new or overly complex device elements.
Solution Approach 2:
The invention controls plasma properties by adjusting parameters (phase, amplitude, direction) of existing waveguide components rather than changing the fundamental structure. This allows optimization of plasma density and uniformity through parameter tuning of simple components rather than complex structural modifications.
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 configuration enables the generation of high-density, high-uniformity plasma, enhancing processing speed and uniformity for large-diameter wafers by effectively rotating the μ wave and controlling reflective waves, thus stabilizing the plasma across varying plasma densities.
Implementation Method 1
a μ-wave generation unit (19) for generating μ waves
Implementation Method 2
there is provided a unit for controlling phases of electric fields which propagate within the rectangular waveguides
Implementation Method 3
a tuning box connected to the waveguide, merging the μ-waves, and controlling reflection of the μ-waves
Implementation Method 4
generating plasma using a high-frequency wave
Implementation Method 5
the plasma generation is executable in the used process area ranging from an about 0.1-Pa low-pressure area to an about 10-Pa high-pressure area
Implementation Method 6
The circularly polarized wave refers to an electromagnetic wave whose electric-field direction rotates one turn during one period within a plane perpendicular to a traveling direction of the electromagnetic wave
Implementation Method 7
a reflection control chamber to manage reflective waves
Data Source
AI summary
A plasma processing apparatus for generating highly-uniform and stable plasma. In an apparatus for generating plasma by using a μ wave, concerning a method for rotating the μ wave in terms of time, a plurality of (larger than two and smaller than four) waveguides are used, then forming an angle between the respective waveguides, and setting a phase difference between respective electric fields therein. This configuration allows introduction of the circularly polarized wave into a processing chamber. At this time, there are provided configuration components such as a waveguide locating method, a unit therefor, a μ-wave merging box, and a reflective-wave control unit using a reflection control chamber.