Shower Plate Aperture Segmentation for Plasma Deposition
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Solution Overview
Problem
Conventional shower plates in plasma deposition apparatuses lack the ability to control gas flow rates on an area-by-area basis, making it difficult to optimize the residence time of precursor gases over semiconductor substrates, which affects film uniformity and quality.
Innovation Solution
The shower plate design features a plurality of apertures on the rear surface extending to the front surface, with separate first and second apertures for carrier and dry gases, allowing independent control of gas flow to the inner and outer areas of the substrate, enabling precise adjustment of residence time through varying flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional shower plate with uniform apertures is used, then the structure is simple and easy to manufacture, but the gas flow rate cannot be controlled on an area-by-area basis, making it difficult to optimize residence time and film uniformity
Solution Approach 1:
The shower plate is segmented into multiple aperture groups (first aperture group, second aperture group, third aperture group) with different aperture densities. The first aperture group has a first aperture density, the second aperture group has a second aperture density different from the first, and the third aperture group has a third aperture density different from both. This segmentation allows different gas flow rates to different areas of the substrate, enabling optimization of residence time and film uniformity across the substrate surface.
Solution Approach 2:
Different regions of the shower plate are designed with different aperture densities to provide locally optimized gas distribution. The first aperture group is positioned to provide a first gas flow rate to a first area of the substrate, the second aperture group provides a second gas flow rate to a second area, and the third aperture group provides a third gas flow rate to a third area. This local quality approach ensures that each region receives the appropriate gas flow for optimal film deposition.
2Loss of time
If the gas flow rate is increased uniformly across the shower plate, then the residence time of precursor gas is extended, but the film uniformity deteriorates due to excessive gas accumulation in certain areas
Solution Approach 1:
The aperture groups are segmented with different densities to control gas flow distribution. By having the first aperture group with a first aperture density, the second aperture group with a second aperture density, and the third aperture group with a third aperture density, the system can extend residence time in areas where it is needed while preventing excessive gas accumulation in other areas, thus maintaining film uniformity.
Solution Approach 2:
The local quality of gas flow is optimized by assigning different aperture densities to different aperture groups. The first aperture group provides a first gas flow rate to a first area, the second aperture group provides a second gas flow rate to a second area, and the third aperture group provides a third gas flow rate to a third area. This ensures that residence time is extended locally where needed without causing uniform film quality deterioration.
3Manufacturing precision
If the gas flow rate is decreased uniformly across the shower plate, then the film uniformity is improved by preventing gas accumulation, but the residence time of precursor gas is insufficient, reducing reaction efficiency
Solution Approach 1:
The segmented aperture groups allow the system to maintain film uniformity by preventing excessive gas accumulation in areas where it would occur, while simultaneously maintaining sufficient residence time in areas where it is needed for efficient reactions. The first aperture group, second aperture group, and third aperture group each provide appropriately scaled gas flow rates to their respective areas.
Solution Approach 2:
The local quality approach ensures that gas flow rates are optimized for each specific area. The first aperture group provides a first gas flow rate to a first area, the second aperture group provides a second gas flow rate to a second area, and the third aperture group provides a third gas flow rate to a third area. This prevents uniform gas accumulation that would harm film uniformity while ensuring sufficient residence time locally to maintain reaction efficiency.
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 enhances film uniformity and quality by allowing optimal control of gas residence time, increasing reaction efficiency on the substrate, as demonstrated by experimental results showing increased or decreased reaction rates based on adjusted gas flow ratios.
Implementation Method 1
The precursor gas is usually directed downwardly with the aid of a carrier gas via a plurality of apertures of a shower plate located at the top of the chamber. A dry gas (e.g., a reactant gas or a purge gas) is also directed downwardly via the same plurality of apertures of the shower plate
Implementation Method 2
it has been practicably difficult to change the flow rate of the gas from the plurality of holes of the shower plate on an area-by-area basis (e.g., the inner part and outer part of the shower plate) such that the residence time of a precursor gas or a reactant gas around the surface of the workpiece can be controlled
Data Source
AI summary
A shower plate for a plasma deposition apparatus, the shower plate including: a plurality of apertures each extending from a rear surface of the shower plate to a front surface for passing a carrier gas therethrough in this direction to a chamber, a plurality of first apertures each extending from a first connecting aperture to an inner part of the front surface for passing gas therethrough in this direction to the chamber, and a plurality of second apertures each extending from a second connecting aperture to an outer part of the front surface for passing gas therethrough in this direction to the chamber, wherein the first connecting aperture connects the first apertures to at least one first aperture extending from a sidewall side of the shower plate and the second connecting aperture connects the second apertures to at least one second aperture extending from the sidewall side.