Electrode Structure with Symmetric Gas Distribution for Plasma Etching
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Solution Overview
Problem
Existing substrate processing apparatuses experience micro abnormal discharge (arcing) during etching processes, which can damage semiconductor devices on wafers, due to non-uniform plasma density distribution caused by uneven electric field and gas supply configurations.
Innovation Solution
A substrate processing apparatus with a disc-like electrode structure featuring buffer chambers and connecting sections arranged symmetrically around the center, ensuring uniform gas distribution and electric field generation, preventing arcing by optimizing the placement of connecting sections at equal intervals on the circumference of the electrode structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If connecting sections are arranged at the same angle in the same radial direction, then gas supply control is simplified, but abnormal discharge (arcing) occurs on the wafer
Solution Approach 1:
The connecting sections are arranged asymmetrically with respect to the radial direction from the center of the shower head. Specifically, the connecting sections are positioned at different angles so that they do not lie on the same radial line, thereby preventing the formation of symmetric electric field patterns that lead to arcing while maintaining adequate gas distribution
2Manufacturing precision
If buffer chambers are provided with separate gas supply systems, then plasma density uniformity is improved, but device complexity increases
Solution Approach 1:
The gas supply system is segmented into multiple independent gas supply systems, with each buffer chamber connected to its own separate gas supply system. This allows independent control of gas flow to each buffer chamber, enabling precise adjustment of plasma density distribution across the wafer surface
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 solution ensures uniform plasma density distribution, preventing arcing and improving etching process consistency by maintaining a symmetrical electric field and gas supply configuration, resulting in more uniform etching rates across the wafer.
Implementation Method 1
the mounting stage 62 and the shower head 63 supply high-frequency power to the inside of the chamber 61, so that an electric field is generated in the chamber 61
Implementation Method 2
The electric field generates plasma from the processing gas, so that the plasma performs plasma processing to the wafer W
Data Source
AI summary
A substrate processing apparatus capable of preventing the abnormal discharge from being generated on a substrate. A housing chamber houses the substrate. A mounting stage arranged in the housing chamber, is configured to enable the substrate to be mounted thereon. A disc-like electrode structure is connected to a high-frequency power supply, and connected to a gas supply apparatus via at least one gas supply system. The electrode structure has therein at least one buffer chamber and a plurality of connecting sections connected to the gas supply system. The buffer chamber is communicated with the inside of the housing chamber via a number of gas holes, and is communicated with the gas supply system via the plurality of connecting sections. The plurality of connecting sections for the buffer chamber are arranged on the circumference of a circle centering around the center of the electrode structure at equal intervals.