Process Shield Gas Curtain for PVD Arc Prevention
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Solution Overview
Problem
In plasma process chambers, high pressure processes lead to contaminants like outgassing particles entering the dark space between the target and the process shield, causing unwanted arcing due to the lack of effective gas distribution and containment.
Innovation Solution
The introduction of a process shield with annular trenches and slots, coupled with inlets for a gas supply, creates a gas curtain in the dark space, preventing contaminants from entering and ensuring uniform gas distribution, thereby preventing arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional process shield is used without gas distribution channels, then the device complexity is low, but contaminants can enter the dark space causing arcing and reliability deteriorates
Solution Approach 1:
The process shield is segmented with multiple annular trenches (first, second, third trenches) divided by radial partitions, creating separate gas distribution zones. This segmentation allows controlled gas flow through specific channels to different regions of the dark space, preventing contaminant ingress while maintaining structural organization and reliability.
Solution Approach 2:
Gas acts as an intermediary substance flowing through the annular trenches and slots to create a protective gas curtain in the dark space. This gas mediator prevents direct contact between contaminants and the dark space, eliminating arcing without requiring complex mechanical barriers or seals.
2Manufacturing precision
If gas distribution channels are added to the process shield, then uniform gas distribution is improved, but the device complexity increases
Solution Approach 1:
Different regions of the process shield are assigned different local qualities through the annular trench configuration. The first trench receives process gas while the second and third trenches receive purge gas, creating localized gas distribution zones. Radial partitions ensure each region receives appropriate gas flow for its specific function, achieving uniform distribution across the dark space.
Solution Approach 2:
The gas distribution system transitions from a two-dimensional surface to a three-dimensional network of annular trenches and radial partitions. This dimensional expansion creates multiple flow paths and distribution zones, enabling uniform gas delivery throughout the dark space volume while integrating seamlessly into the process shield structure.
3Manufacturing precision
If the process shield includes multiple annular trenches and partitions, then gas distribution uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The process shield is segmented into multiple functional zones using annular trenches and radial partitions, allowing independent optimization of gas flow paths. This segmentation enables precise control over gas distribution uniformity while maintaining modular manufacturing approaches that can simplify fabrication of complex geometries.
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 effectively prevents arcing by maintaining a controlled gas environment in the dark space, ensuring consistent and efficient plasma processing across varying pressures.
Implementation Method 1
A gas supply is provided in communication with the plurality of annular trenches to supply a gas to the dark space
Implementation Method 2
RF power is provided to the plasma process chamber to create a plasma in a processing volume disposed between the target and the substrate support
Implementation Method 3
The target provides a source of material for sputtering onto the substrate during processing
Data Source
AI summary
Embodiments of process shield for use in process chambers are provided herein. In some embodiments, a process shield for use in a process chamber includes: an annular body having an upper portion and a lower portion extending downward and radially inward from the upper portion, wherein the upper portion includes a plurality of annular trenches on an upper surface thereof and having a plurality of slots disposed therebetween to fluidly couple the plurality of annular trenches, wherein one or more inlets extend from an outer surface of the annular body to an outermost trench of the plurality of annular trenches.