Plasma Chamber Waveguide Shielding for Uniform RF Generation
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Solution Overview
Problem
Existing plasma processing apparatuses face challenges in satisfactorily introducing radio frequency waves into the space between an upper electrode and a stage, leading to inefficient plasma generation and uniformity.
Innovation Solution
The apparatus incorporates a waveguide configured to emit radio frequency waves in the VHF or UHF band, with a conductive part extending between the stage and the processing container's side wall, ensuring efficient introduction and shielding of these waves, and includes an insulating member to prevent peripheral discharge, maintaining uniform plasma density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If radio frequency waves are introduced into the space between upper electrode and stage, then plasma generation efficiency is improved, but radio frequency waves may diffract to regions extending under the stage causing non-uniform plasma distribution
Solution Approach 1:
A conductive part is introduced as an intermediary element between the stage and the region below it. This conductive structure acts as a barrier that prevents radio frequency wave diffraction into unwanted regions while allowing the waves to effectively generate plasma in the intended space between the upper electrode and stage, thus maintaining plasma uniformity without sacrificing generation efficiency
Solution Approach 2:
The harmful diffraction effect of radio frequency waves is extracted and isolated by positioning the conductive part to block the propagation path. This separates the useful plasma generation function from the harmful wave diffraction, allowing the former to proceed efficiently while the latter is contained and prevented from affecting plasma uniformity
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 allows for effective introduction of radio frequency waves, resulting in uniform plasma generation and processing of substrates with sufficient intensity, ensuring consistent plasma processing outcomes.
Implementation Method 1
The waveguide is configured to introduce radio frequency waves in a VHF band or a UHF band into the space
Implementation Method 2
The conductive part is electrically connected to the metal layer and the side wall of the processing container while extending from the outer peripheral portion toward the side wall so that the radio frequency waves emitted from the end portion are introduced into the space
Data Source
AI summary
A plasma-processing apparatus includes a processing container, a stage provided within the processing container, an upper electrode provided above a front surface of the stage, with a space within the processing container interposed therebetween, a waveguide configured to introduce radio-frequency waves in a VHF/UHF band into the space, and a conductive part extending between the outer peripheral portion of the stage and a side wall of the processing container. The stage includes a metal layer. Its outer peripheral portion includes a part of the metal layer. The waveguide includes an end portion from which radio-frequency waves are emitted. The end portion is disposed to face the space. The side wall is grounded. The conductive part is electrically connected to the metal layer and the side wall while extending from the outer peripheral portion toward the side wall so that the radio-frequency waves are introduced into the space.