Plasma Electrode Structure for Uniform Large-Area Substrate Processing
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Solution Overview
Problem
Conventional substrate processing apparatuses fail to optimize gas flow rate and plasma density distribution, leading to inefficient substrate processing and non-uniform thin film formation, especially in large-area processing.
Innovation Solution
The substrate processing apparatus features a second electrode with insertion holes having a gradually increasing opening area from the center to the edge, and a concave dome-shaped lower surface, which reduces gas flow rate at the edge, increasing residence time and plasma density, thereby enhancing processing efficiency and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas is supplied uniformly through flat electrodes with equal-diameter gas supply passages, then the device structure is simple, but the gas flow rate and residence time are not optimized, leading to non-uniform plasma density and poor processing efficiency
Solution Approach 1:
The patent applies local quality by making the electrode structure non-uniform: the lower electrode has insertion holes with different diameters at different locations (smaller at center, larger at edge), and the upper electrode has gas supply passages with different diameters (smaller at center, larger at edge). This local variation optimizes gas flow distribution and plasma density uniformity across the substrate surface, directly improving processing efficiency without requiring complex external control systems.
Solution Approach 2:
The patent employs curvature by designing the lower electrode with a concave dome-shaped surface and the upper electrode with a convex dome-shaped surface. This curved geometry, combined with the radially varying hole/passages diameters, creates optimized gas flow paths that increase residence time at the substrate edge while maintaining appropriate flow at the center, thereby achieving uniform plasma density and improving processing efficiency.
2Quantity of substance
If gas flow rate is high at the edge of the substrate, then gas supply is sufficient, but the residence time is reduced, leading to lower plasma density and non-uniform thin film formation
Solution Approach 1:
The patent applies local quality by varying the insertion hole diameters in the lower electrode and gas supply passage diameters in the upper electrode according to radial position. The holes/passages are smaller at the center and larger at the edge, which compensates for the naturally higher flow velocity at the edge. This local optimization ensures that gas residence time is extended at the edge where it is naturally shorter, while maintaining adequate gas supply quantity across the entire substrate area, resulting in uniform plasma density.
3Duration of action of moving object
If the opening area of insertion holes is increased from center to edge, then gas residence time is extended at the edge, but the gas flow rate distribution becomes non-uniform
Solution Approach 1:
The patent applies local quality by implementing a graduated variation in opening areas rather than uniform sizing. The insertion holes in the lower electrode and gas supply passages in the upper electrode have diameters that increase progressively from center to edge. This gradual local adjustment optimizes the balance between gas flow rate and residence time at different radial positions, extending residence time at the edge while maintaining appropriate flow rate distribution across the substrate.
Solution Approach 2:
The patent employs curvature by combining the radially varying opening areas with dome-shaped electrode surfaces. The concave lower electrode and convex upper electrode create curved gas flow paths that work synergistically with the varying hole/passages diameters. This curved geometry further optimizes gas flow distribution and residence time, achieving uniform plasma density while maintaining proper gas flow rate distribution.
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 results in improved substrate processing efficiency by extending gas residence time and increasing plasma density, leading to more uniform thin film formation on substrates.
Implementation Method 1
a second electrode positioned beneath the first electrode and having a plurality of insertion holes into which the respective protruding electrodes are inserted. Each of the insertion holes of the second electrode includes a first hole at its upper portion, an associated one of the protruding electrodes being inserted into the first hole, and a second hole at its lower portion facing the upper portion
Implementation Method 2
form a uniform thin film by increasing a plasma density
Data Source
AI summary
The present disclosure relates to a substrate processing apparatus capable of improving efficiency in a substrate processing process by adjusting a flow rate and residence time of gas and a plasma density according to process conditions. The substrate processing apparatus according to the embodiment of the present disclosure is advantageous in that it can enhance efficiency in the substrate processing process by decreasing the flow rate and increasing residence time of gas and the plasma density in the process of supplying the gas through the shape forming of the gas injection module including the first and second injection plates.