Anti-Deposition Shield Labyrinth Structure for Sputter Particle Control
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Solution Overview
Problem
Existing film forming apparatuses face challenges in efficiently suppressing sputter particles from wrapping around the processing container walls and target holder components, leading to adverse effects on the processing quality and stability of metal oxide film formation.
Innovation Solution
The apparatus incorporates an anti-deposition shield with a labyrinth structure and an insulating film, such as Al2O3, to prevent sputter particles from adhering to the target holder and processing container walls, while regulating the emission direction and suppressing arc discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional anti-deposition member is used to suppress sputter particles, then particle attachment on container walls is reduced, but sputter particles still wrap around target holder components causing film formation instability
Solution Approach 1:
The anti-deposition shield is divided into multiple sections: a main body portion covering the target holder, and a labyrinth portion with multiple folds extending toward the target. This segmentation allows different sections to perform different functions - the main body blocks direct particle attachment while the labyrinth portion intercepts wrapping particles without contacting the target, resolving the contradiction between reducing particle attachment and maintaining film stability.
Solution Approach 2:
The anti-deposition shield acts as an intermediary component positioned between the target and target holder. It intercepts sputter particles before they can wrap around the target holder, preventing both particle attachment and the harmful effects on film formation stability, thus serving as a mediator that protects the system without interfering with the sputtering process.
2Object-affected harmful factors
If the anti-deposition shield extends close to the target to improve particle suppression, then particle wrapping is reduced, but micro arc discharges occur between the shield and target
Solution Approach 1:
The anti-deposition shield is positioned in the radial dimension between the target and target holder, rather than extending axially close to the target surface. By utilizing the radial space and creating a labyrinth structure with multiple folds, the shield intercepts wrapping particles in a different spatial dimension, achieving particle suppression without approaching the target close enough to cause micro arc discharges.
Solution Approach 2:
The anti-deposition shield performs preliminary interception of sputter particles before they can wrap around the target holder and reach positions where they would cause micro arc discharges. By catching particles early in their trajectory through the labyrinth structure, the shield prevents the conditions that lead to arc discharge while maintaining safe distance from the target.
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 effectively reduces the occurrence of micro arc discharges and enhances the stability of metal oxide film formation, ensuring consistent film quality and reduced particle attachment on the apparatus components.
Implementation Method 1
a target made of metal, including a main body and an annular flange provided around the main body, and configured to emit sputter particles from the main body
Implementation Method 2
an anti-deposition shield provided around the main body of the target to cover the flange, a target clamp, and the target holder
Data Source
AI summary
A film forming apparatus includes: a processing container; a substrate holder that holds the substrate in the processing container; and a target assembly disposed in an upper side of the substrate holder. The target assembly includes: a target made of metal, including a main body and a flange provided around the main body, and emitting sputter particles from the main body; a target holder including a target electrode configured to supply power to the target, and holding the target; a target clamp that clamps the flange of the target to the target holder; and an anti-deposition shield provided around the main body of the target to cover the flange, the target clamp, and the target holder, and having a labyrinth structure in which an inner tip end thereof is disposed to enter a recess between the main body of the target and the target clamp.