Heated Plasma Showerhead for Ion-Filtered Etch Uniformity
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Solution Overview
Problem
Substrate processing systems face challenges in controlling plasma exposure, particularly with RF plasma, which can damage sensitive materials and affect the uniformity of etching processes due to ion-generated effects.
Innovation Solution
A showerhead with an embedded heater and a controller to regulate temperature, combined with a faceplate pattern of holes that can be blocked in specific regions, is used to filter ions and control plasma uniformity, maintaining desired etch profiles by optimizing the gap between the showerhead and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If RF plasma is used to activate chemical reactions, then deposition and etching processes can be performed, but ions generated within the plasma can damage sensitive materials and adversely affect device performance
Solution Approach 1:
The plasma generation is separated into two distinct zones: an upstream plasma chamber where plasma is generated, and a downstream processing chamber where substrate processing occurs. This spatial segmentation allows plasma to be generated remotely, reducing direct ion exposure to the substrate while maintaining processing capability through radical transport across the chamber boundary.
Solution Approach 2:
A plasma filter or aperture structure acts as an intermediary between the plasma source and substrate processing zone. This intermediary selectively transmits reactive radicals while blocking or reducing ion flux, enabling chemical reactions to proceed on the substrate without the damaging effects of direct ion bombardment.
2Reliability
If Ions are generated within the plasma, then chemical reactions can be activated, but the ions can modify the properties of device materials and adversely affect the performance of the overall structure
Solution Approach 1:
The plasma generation is separated into two distinct zones: an upstream plasma chamber where plasma is generated, and a downstream processing chamber where substrate processing occurs. This spatial segmentation allows plasma to be generated remotely, reducing direct ion exposure to the substrate while maintaining processing capability through radical transport across the chamber boundary.
Solution Approach 2:
A plasma filter or aperture structure acts as an intermediary between the plasma source and substrate processing zone. This intermediary selectively transmits reactive radicals while blocking or reducing ion flux, enabling chemical reactions to proceed on the substrate without the damaging effects of direct ion bombardment.
3Manufacturing precision
If a conventional showerhead design is used, then plasma can be delivered to the substrate, but etching uniformity cannot be optimized due to uncontrolled ion exposure
Solution Approach 1:
The plasma generation is separated into two distinct zones: an upstream plasma chamber where plasma is generated, and a downstream processing chamber where substrate processing occurs. This spatial segmentation allows plasma to be generated remotely, reducing direct ion exposure to the substrate while maintaining processing capability through radical transport across the chamber boundary.
Solution Approach 2:
The system changes the fundamental parameters of plasma delivery by transitioning from direct plasma contact to remote plasma generation. This parameter change enables independent control of radical flux and ion flux, allowing optimization of etching uniformity through adjusted gas flow rates, pressure gradients, and aperture configurations.
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 enhances etch uniformity and reduces material variation across substrates, ensuring consistent processing outcomes by filtering ions and controlling plasma flow.
Implementation Method 1
A showerhead for a processing chamber in a substrate processing system includes an upper portion having a lower surface and an upper surface and a faceplate... A heater is embedded in the upper portion of the showerhead
Implementation Method 2
In some applications, radio frequency (RF) plasma such as inductively coupled plasma (ICP) may be used to activate chemical reactions
Data Source
AI summary
A showerhead for a processing chamber in a substrate processing system includes an upper portion having a lower surface and an upper surface and a faceplate. A lower surface of the faceplate is below the lower surface of the upper portion such that the showerhead extends into an interior volume of the processing chamber and the faceplate includes a plurality of holes arranged in a pattern to provide fluid communication between a remote plasma source above the showerhead and the interior volume of the processing chamber. A sidewall extends upward from an outer edge of the faceplate between the faceplate and the upper portion and the upper portion extends radially outward from the sidewall of the showerhead and is configured to be mounted on a sidewall of the processing chamber. A heater is embedded in the upper portion of the showerhead.