PVD Process Kit Centering Mechanism for Uniform Gas Distribution
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Solution Overview
Problem
Conventional process kits for physical vapor deposition (PVD) chambers face issues with contamination, non-uniform gas distribution, and limited adjustability, leading to inefficiencies in film deposition and component wear.
Innovation Solution
A process kit comprising an interleaving ground shield, cover ring, and centering mechanism that allows for adjustable spacing, controlled gas flow, and even gap maintenance between components, ensuring uniform gas distribution and reduced contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ring and shield designs are used, then the processing chamber can operate, but particulate contamination occurs due to periodic contact between components
Solution Approach 1:
The patent extracts and eliminates the problematic periodic contact mechanism between the cover ring and shield by introducing a centering mechanism with spacing elements that maintain a controlled gap, preventing the components from contacting each other during pedestal movement
Solution Approach 2:
The patent introduces a centering mechanism with spacing elements as an intermediary between the cover ring and shield, which maintains a controlled gap and prevents direct contact between the two components, thereby eliminating the contamination source
2Stability of the object's composition
If the cover ring is centered relative to the pedestal, then the assembly is stable, but non-uniform gaps are created between the cover ring and shield leading to non-uniform gas distribution
Solution Approach 1:
The patent employs asymmetric positioning of the cover ring relative to the pedestal, where the cover ring is offset from the pedestal center to align with the shield center, creating a symmetric gap between the cover ring and shield while maintaining stable positioning through the centering mechanism
Solution Approach 2:
The patent introduces a dynamic centering mechanism with adjustable spacing elements that can adapt to different pedestal positions and maintain a controlled, uniform gap between the cover ring and shield, ensuring uniform gas distribution while preserving positioning stability
3Volume of stationary object
If the substrate surface is at or near the top of the cover ring, then the chamber volume is maximized, but reactive species concentrate near the edges of the substrate
Solution Approach 1:
The patent applies local quality by positioning the substrate surface below the top of the cover ring, creating a specific regional configuration where the cover ring overhangs the substrate. This local structural adjustment prevents reactive species concentration at the substrate edges while maintaining sufficient chamber volume for effective processing
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 solution enhances film uniformity and repeatability, extends chamber component life, and minimizes plasma leakage, resulting in improved deposition efficiency and reduced contamination within the chamber.
Implementation Method 1
maintain a controlled gap between the shield and the cover ring to improve gas conductance through the gap
Implementation Method 2
Physical vapor deposition (PVD), or sputtering, is one of the most commonly used processes in the fabrication of electronic devices
Implementation Method 3
PVD is a plasma process performed in a vacuum chamber where a negatively biased target is exposed to a plasma of an inert gas
Data Source
AI summary
Embodiments of the invention generally provide a process kit for use in a physical deposition chamber (PVD) chamber. In one embodiment, the process kit provides adjustable process spacing, centering between the cover ring and the shield, and controlled gas flow between the cover ring and the shield contributing to uniform gas distribution, which promotes greater process uniformity and repeatability along with longer chamber component service life.