Flared Shutter Liner Reduces CVD Gap Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional shutter liners in chemical vapor deposition systems allow reactants to escape through a large horizontal gap, leading to deposition and particulate matter formation, which contaminates wafers and reduces device yield.
Innovation Solution
A flared shutter liner with a cylindrical upper portion and outwardly flared lower portion is designed to occupy the horizontal gap between inner and outer liners, reducing reactant migration and deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a traditional cylindrical shutter liner is used, then the structure is simple and easy to manufacture, but reactants escape through the horizontal gap causing deposition and particulate matter formation
Solution Approach 1:
The shutter liner incorporates a flared lower portion with an outwardly angled wall surface that curves away from the reaction volume. This curved geometry occupies the horizontal gap between the inner and outer liners, physically blocking reactant migration paths while maintaining manufacturing feasibility through standard forming techniques.
Solution Approach 2:
The shutter liner transitions from a simple cylindrical shape to a three-dimensional structure with a flared lower portion. This adds a radial dimension to the liner design, allowing it to protrude into the horizontal gap and create a physical barrier against reactant escape without significantly increasing manufacturing complexity.
2Object-affected harmful factors
If a flared shutter liner is used, then reactant migration is reduced, but the device complexity increases
Solution Approach 1:
The shutter liner is divided into two distinct portions: an upper cylindrical portion and a lower flared portion. This segmentation allows each portion to serve its specific function - the cylindrical upper portion maintains structural simplicity while the flared lower portion provides reactant migration blocking. The segmented design can be manufactured as a single piece or assembled from multiple components.
3Manufacturing precision
If the shutter liner occupies the horizontal gap, then deposition is reduced, but the wafer carrier access may be affected
Solution Approach 1:
The shutter liner is designed as a movable component that can be positioned in different locations within the reaction chamber. During wafer loading operations, the shutter liner can be repositioned to clear the wafer carrier access path, allowing easy insertion and removal of wafers. During deposition operations, the shutter liner is positioned to occupy the horizontal gap and block reactant migration. This dynamic positioning resolves the conflict between deposition control and operational ease.
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 flared shutter liner significantly reduces deposition rates by 91%, minimizing wafer contamination and improving device yield.
Implementation Method 1
reactants can escape (through diffusion, back-streaming, etc.) in through this large horizontal gap
Implementation Method 2
These reactants can then produce particulate matter through gas flow recirculation, condensation, etc., and produce defects in many locations in the reactor
Implementation Method 3
In MOCVD, reactant gases are introduced into a reactor chamber within a controlled environment that enables the reactant gas to react on a substrate to grow thin epitaxial layers
Data Source
AI summary
A shutter liner for use in a chemical vapor deposition (CVD) system includes an upper portion that has a cylindrical shape and a lower portion that has an outwardly flared shape. The outwardly flared shape reduces deposition within the reaction chamber by providing an outwardly angled wall surface that occupies a horizontal gap between inner and outer liners that are contained within the reaction chamber.