CVD Carrying Ring Edge Geometry for Parasitic Deposit Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In devices used for depositing SiC layers, particle formation on the peripheral edge of the carrying ring occurs, leading to whisker, dendrite, or tooth-shaped parasitic deposits that negatively affect the deposition result.
Innovation Solution
The peripheral edge of the carrying ring is rounded or chamfered to reduce particle deposition, with a rounding radius of at least 0.1 mm and preferably greater than 0.2 mm, or a chamfer width of 0.2 mm to 0.5 mm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the upper face of the carrying ring transitions into a cylinder inner face in a sharp-edged manner, then the structure is simple and easy to manufacture, but particle formation occurs on the peripheral edge leading to parasitic deposits
Solution Approach 1:
The patent applies curvature by rounding the peripheral edge of the carrying ring instead of maintaining a sharp edge. The rounded edge has a radius r that is at least 0.1 mm, preferably at least 0.2 mm. This curvature eliminates the sharp transition between the upper face and the cylinder inner face, preventing particle formation and parasitic deposits while maintaining manufacturing feasibility through standard rounding processes.
2Object-generated harmful factors
If the rounding radius is increased to prevent particle deposition, then parasitic deposits are reduced, but the device complexity increases
Solution Approach 1:
The patent changes the geometric parameter of the carrying ring edge from a sharp corner to a rounded edge with a specific radius range (at least 0.1 mm, preferably at least 0.2 mm). This parameter modification effectively reduces particle formation and parasitic deposits without significantly increasing device complexity, as the rounding can be achieved through standard manufacturing processes.
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 rounded or chamfered edge significantly diminishes the formation of parasitic deposits, improving the deposition result by preventing particle accumulation on the edge of the carrying ring.
Implementation Method 1
The process chamber or the wide side plane of the susceptor assembly that faces the process chamber is heated to process temperatures at which the starting materials, which can be silane and methane or other silicon-hydrogens or carbon-hydrogens, decompose
Implementation Method 2
edges of the essentially circular substrates rest on support surfaces of the carrying ring
Implementation Method 3
The peripheral edge of the carrying ring is rounded or chamfered to reduce particle deposition, with a rounding radius of at least 0.1 mm and preferably greater than 0.2 mm, or a chamfer width of 0.2 mm to 0.5 mm
Data Source
AI summary
A susceptor assembly, which is situated in a reactor housing, has at least one wide side plane that faces a process chamber, at least one pocket, and a carrying element that lies in the at least one pocket, for carrying and handling a substrate. An upper face of the carrying element is adjacent to a limiting face of a recess in which the substrate is arranged. A section of the limiting face which runs along a cylinder inner lateral face merges into the upper face of the carrying element, forming a rounded edge or chamfer. To reduce the growth of parasitic deposits on an inner edge of the carrying element, the section of the limiting face which runs along the cylinder inner lateral face has a height which is greater than the material thickness of the substrate, and the radius of the rounded edge is greater than 0.4 mm.