Substrate Support RF Return Path Segmentation
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Solution Overview
Problem
Thermocouples and AC power leads in substrate processing systems are adversely affected by RF noise due to their position in the RF return path, leading to inaccurate temperature measurements.
Innovation Solution
A substrate support system with a conductive element that includes an RF gasket and features to engage the gasket, shortening the RF grounding path and preventing RF noise interference, while also incorporating a heat transfer body and an annular biasable element to enhance RF return and temperature measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If thermocouples and AC power leads are positioned in the RF return path, then they can be integrated into the substrate support structure, but RF noise interferes with temperature measurements
Solution Approach 1:
The patent segments the RF return path by providing a dedicated RF return conductor separate from the thermocouple and AC power lead paths. This segmentation isolates the sensitive measurement and power circuits from the high-frequency RF currents, eliminating noise interference while maintaining structural integration.
Solution Approach 2:
The patent introduces an intermediary RF return conductor that carries RF currents away from the thermocouple and power lead region. This intermediary element acts as a shield and separate current path, preventing RF noise from coupling into the sensitive measurement circuits.
2Ease of manufacture
If the RF grounding path is lengthened to accommodate existing structures, then integration is easier, but RF noise interference increases
Solution Approach 1:
The patent extracts the RF return path from the existing structural elements and provides it as a separate, dedicated conductor. This allows the RF grounding path to be optimized for minimal length and impedance without compromising the integration of other components, as the RF return is taken out as an independent element.
Solution Approach 2:
The patent resolves the conflict by adding another dimensional aspect to the conductor arrangement - providing multiple conductors (RF return, thermocouple, power leads) that are spatially separated in different dimensions or planes, allowing each to be optimized independently for its specific function.
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 reduces RF noise interference, ensuring accurate temperature measurements and efficient heat transfer during substrate processing by minimizing the RF current grounding path and electric field within the substrate support system.
Implementation Method 1
the conductive element includes features that engage the RF gasket to return the RF current to ground
Implementation Method 2
a heat transfer body to transfer heat to or from the substrate support
Implementation Method 3
the annular biasable element contacts the adapter portion when the substrate support is in a processing position
Data Source
AI summary
Apparatus for processing a substrate are provided herein. In some embodiments, a substrate support includes a body having a support surface; an RF electrode disposed in the body proximate the support surface to receive RF current from an RF source; a shaft to support the body; a conductive element having an interior volume and extending through the shaft, wherein the conductive element is coupled to the RF electrode; and an RF gasket; wherein the conductive element includes features that engage the RF gasket to return the RF current to ground.