Multi-zone Gas Injection Upper Electrode for Plasma Uniformity
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Solution Overview
Problem
Plasma processing in plasma chambers is not uniform across the center to edge of substrates due to limitations in temperature control and gas distribution, leading to inconsistent etch rates.
Innovation Solution
A plasma processing system with a multi-zone upper electrode featuring concentric gas injection zones, dual temperature control, and RF power sources, allowing for independent temperature adjustment and gas distribution to manipulate plasma processing conditions radially across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single showerhead type upper electrode with evenly distributed outlet ports is used, then gas distribution is uniform, but plasma processing is not uniform across the center to edge of the substrate
Solution Approach 1:
The upper electrode is segmented into multiple concentric gas injection zones with different gas distribution characteristics. Each zone can independently control gas flow and temperature profiles, enabling differentiated plasma processing in central and edge regions to achieve uniform overall processing results
Solution Approach 2:
Different regions of the upper electrode are designed with locally optimized gas injection characteristics. The central zone and edge zone have different gas flow rates, temperatures, and compositions tailored to their specific processing requirements, allowing precise control over plasma uniformity across the substrate
2Manufacturing precision
If temperature control is applied to the upper electrode, then plasma processing can be manipulated, but thermal ramp-up time increases
Solution Approach 1:
The temperature control system is segmented into multiple independent heating zones corresponding to different gas injection zones. Each zone can be heated independently and simultaneously, allowing parallel temperature adjustment that reduces overall ramp-up time while maintaining precise plasma processing control
Solution Approach 2:
The upper electrode and gas distribution system are pre-configured with integrated heating elements and gas channels during manufacturing. This preliminary preparation eliminates the need for sequential assembly and reduces thermal ramp-up time by enabling immediate simultaneous heating of all zones when processing begins
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 approach enables precise control over etch rates by varying temperatures and gas concentrations, achieving uniform plasma processing and consistent results across the substrate, improving processing speed and reducing thermal ramp-up time.
Implementation Method 1
The gas distribution layer 110 includes multiple gas passages 112, 114 to distribute the process gases evenly to the ports 106 across the surface layer 104
Implementation Method 2
The temperature control layer 120 includes elements 122. Elements 122 can heat or cool the temperature control layer 120, as desired, to control the temperature of the upper electrode 102
Implementation Method 3
a plasma chamber 100 has a single showerhead type upper electrode 102... as the substrate is being processed by a plasma 150
Data Source
AI summary
A plasma processing system includes a plasma chamber having a substrate support, and a multi-zone gas injection upper electrode disposed opposite the substrate support. An inner plasma region is defined between the upper electrode and the substrate support. The multi-zone gas injection upper electrode has a plurality of concentric gas injection zones. A confinement structure, which surrounds the inner plasma region, has an upper horizontal wall that interfaces with the outer electrode of the upper electrode. The confinement structure has a lower horizontal wall that interfaces with the substrate support, and includes a perforated confinement ring and a vertical wall that extends from the upper horizontal wall to the lower horizontal wall. The lower surface of the upper horizontal wall, an inner surface of the vertical wall, and an upper surface of the lower horizontal wall define a boundary of an outer plasma region, which surrounds the inner plasma region.