Movable Ring Plasma Chamber for Uniform Etching
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Solution Overview
Problem
Conventional plasma processing apparatuses face issues with process uniformity due to gas flow differences between the center and periphery of the substrate, leading to non-uniform processing and increased unnecessary space within the processing chamber, hindering miniaturization.
Innovation Solution
A plasma processing apparatus featuring a vertically movable ring-shaped member around the mounting table, with gas supply and exhaust holes, that forms a processing space only above the substrate, allowing for uniform gas distribution and reduced chamber size by eliminating peripheral space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gas is exhausted downward from the vicinity of the mounting table or upward from the shower head, then gas flow uniformity is improved, but the internal volume of the processing chamber becomes much larger than the substrate size, increasing unnecessary space
Solution Approach 1:
The gas exhaust function is segmented from the mounting table and shower head locations, and redistributed through multiple exhaust holes in the chamber ceiling. This allows gas to be exhausted from directly above the substrate processing area, maintaining process uniformity while eliminating the need for large peripheral exhaust paths.
Solution Approach 2:
The gas exhaust path is repositioned from horizontal exhaust at substrate/shower head level to vertical exhaust through the chamber ceiling. This dimensional change allows the processing chamber to be compact in horizontal dimensions while maintaining effective gas flow control for uniform processing.
2Device complexity
If gas flows from the center of the substrate to the periphery, then gas supply is simplified, but processing state differences occur between center and periphery, deteriorating process uniformity
Solution Approach 1:
The gas exhaust function is segmented into multiple distributed exhaust holes in the chamber ceiling rather than a single peripheral exhaust path. This segmentation creates multiple gas flow paths from the substrate area upward, preventing gas from flowing laterally across the substrate surface and ensuring uniform processing conditions.
Solution Approach 2:
Gas exhaust holes are strategically positioned in the chamber ceiling directly above different regions of the substrate. This local positioning ensures that gas is exhausted from the appropriate locations, maintaining uniform gas distribution and processing conditions across the entire substrate surface.
3Ease of operation
If gas exhaust paths are provided in the vicinity of the mounting table or shower head, then gas flow control is enhanced, but the processing chamber size increases unnecessarily
Solution Approach 1:
The gas exhaust function is moved from the horizontal plane at substrate/shower head level to the vertical dimension through the chamber ceiling. This allows effective gas flow control to be achieved without increasing the horizontal dimensions of the processing chamber, thus reducing unnecessary space.
Solution Approach 2:
The chamber ceiling is given a dual function: it serves as both the enclosure for the processing chamber and as the gas exhaust surface through integrated exhaust holes. This eliminates the need for separate peripheral exhaust structures, reducing the overall chamber volume while maintaining effective gas flow control.
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 enhances surface process uniformity and reduces the apparatus size by minimizing unnecessary space within the processing chamber, ensuring efficient and uniform plasma etching across the substrate.
Implementation Method 1
a shower head for supplying a gas toward a substrate such as a semiconductor wafer in a shower pattern has been conventionally used... in a plasma processing apparatus that performs a plasma etching process on a substrate
Implementation Method 2
a plurality of gas exhaust holes opened in an inner wall of the ring-shaped member to evacuate the processing space
Data Source
AI summary
A plasma processing apparatus includes a shower head that supplies a gas toward a substrate in a shower pattern through a plurality of gas discharge holes provided in a facing surface of the shower head facing a mounting table; a multiple number of gas exhaust holes provided in the facing surface of the shower head; a vertically movable ring-shaped member that is installed along a circumference of the mounting table and is configured to form, at a raised position, a processing space surrounded by the mounting table, the shower head and the ring-shaped member; a multiplicity of gas supply holes opened in an inner wall of the ring-shaped member to supply a gas into the processing space; and a plurality of gas exhaust holes opened in an inner wall of the ring-shaped member to evacuate the processing space.