Dielectric Plasma Showerhead Assembly for Gas-Opening Plasma Attenuation
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Solution Overview
Problem
Existing showerhead assemblies used in high charge and plasma density processes, such as microwave plasma, contribute to defect and particle generation due to plasma light up in gas openings, leading to degradation of o-rings and reduced microwave source reliability.
Innovation Solution
A plasma showerhead assembly with a conductive plate and dielectric faceplate design featuring gas openings, dummy openings, and o-rings to minimize plasma light up, using dielectric resonators and microwave antennas, along with metal inserts in dummy openings to attenuate plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gas openings are provided in the showerhead for precursor delivery, then deposition process functionality is enabled, but plasma lights up in the gas openings causing particle and defect generation
Solution Approach 1:
The showerhead is divided into multiple functional zones: active gas openings for precursor delivery, dummy openings for plasma attenuation, and metal insert elements. This segmentation allows different regions to serve different purposes - some openings deliver gases while others specifically attenuate plasma to prevent particle generation.
Solution Approach 2:
Metal inserts are introduced as intermediary elements within the dummy openings. These metal inserts act as plasma attenuators that intercept and absorb microwave energy, preventing plasma from forming in the gas openings while allowing the gas delivery function to remain intact.
2Productivity
If plasma density is increased for higher deposition rates, then productivity improves, but plasma light up in gas openings increases causing more defects
Solution Approach 1:
The dummy openings with metal inserts convert the harmful high-density plasma into a beneficial plasma attenuation mechanism. The metal inserts intentionally create controlled plasma regions in the dummy openings that absorb excess microwave energy, preventing uncontrolled plasma formation in the gas openings even at high deposition rates.
3Speed
If microwave power is increased for faster processing, then processing speed improves, but plasma-induced damage to o-rings increases
Solution Approach 1:
The harmful plasma is extracted or removed from the gas opening regions through the dummy openings. The metal inserts in the dummy openings act as dedicated plasma sinks that capture and contain plasma formation, preventing plasma from contacting and degrading the o-rings that seal the gas openings.
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
Reduces plasma-induced damage to o-rings, minimizing defects and extending the lifetime of the plasma source by optimizing gas and dummy openings distribution, enhancing process reliability.
Implementation Method 1
a microwave plasma power supply configured to generate a microwave plasma in the dielectric faceplate gas openings of the plasma showerhead assembly
Implementation Method 2
a plurality of dielectric resonators protruding from the first surface and arranged in a pattern and configured to mount through the plurality of resonator openings when assembled
Implementation Method 3
dummy openings that extend through a portion of the faceplate thickness from the first surface or the second surface of the dielectric faceplate
Data Source
AI summary
Plasma showerhead assemblies are disclosed comprising a conductive plate having a plurality of conductive plate openings, a dielectric faceplate having a thickness and a plurality of dielectric faceplate gas openings extending through the dielectric faceplate thickness in fluid communication with the plurality of the conductive plate gas openings. A plurality of dummy openings extend through a portion of the faceplate thickness from of the dielectric faceplate.