Inner Chamber Sidewall Openings for Uniform Plasma Gas Velocity
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Solution Overview
Problem
Existing capacitively-coupled plasma processing apparatuses exhibit variations in gas flow velocity in the radial direction within the substrate processing space, leading to inconsistencies in processing quality.
Innovation Solution
The plasma processing apparatus incorporates an inner chamber with a sidewall portion that gradually increases its opening area from the lower end to the upper end, featuring a higher density and larger through-holes in the upper portion, which reduces gas pressure and flow velocity variations in the radial direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional baffle plate with uniform through-holes is used, then the structure is simple, but the gas flow velocity varies significantly in the radial direction
Solution Approach 1:
The baffle plate is designed with non-uniform through-hole distribution where the density and/or size of through-holes varies in the radial direction. Specifically, the through-hole density decreases from the center toward the periphery, or the through-hole size increases radially outward. This local variation in through-hole characteristics compensates for the natural gas flow distribution, achieving uniform gas flow velocity across the radial direction while maintaining a relatively simple plate structure.
2Manufacturing precision
If the baffle plate opening area is increased to improve gas flow distribution, then the gas flow velocity uniformity improves, but the structural stability and exhaust efficiency may deteriorate
Solution Approach 1:
The baffle plate design modifies the parameters of through-holes (density, size, shape) in the radial direction to achieve optimal gas flow distribution. By carefully controlling these parameter variations, the design achieves uniform gas flow velocity without requiring excessive opening area, thus maintaining structural stability and exhaust efficiency while improving flow 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 design effectively minimizes gas flow velocity variations in the radial direction, enhancing processing uniformity and consistency within the substrate processing space.
Implementation Method 1
The sidewall portion has an opening area that gradually or continuously increases along a direction from a lower end toward an upper end of the sidewall portion
Implementation Method 2
a plasma processing apparatus includes an outer chamber, a substrate support, an upper electrode, an inner chamber, and an exhaust device
Data Source
AI summary
A plasma processing apparatus includes a substrate support, an upper electrode, an inner chamber, and an exhaust device in an outer chamber. The substrate support is provided in the outer chamber. The upper electrode is provided above the substrate support. The inner chamber defines a substrate processing space on the substrate support. The exhaust device is connected to an exhaust port provided at a bottom portion of the outer chamber. The inner chamber includes a ceiling portion and a sidewall portion. The ceiling portion extends on the substrate processing space, provides a plurality of gas holes, and configures a shower head together with the upper electrode. The sidewall portion extends in a peripheral direction to surround the substrate processing space and provides a plurality of through-holes. The sidewall portion has an opening area that increases along a direction from a lower end toward an upper end of the sidewall portion.