Substrate Support Heater RF Return Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate supports in substrate processing systems suffer from inaccurate temperature measurements due to the distortion of electric fields caused by RF current flowing through conductive elements, which interferes with thermocouples and other temperature monitoring devices.
Innovation Solution
Incorporating a conductive element with an interior volume that houses the RF electrode and thermocouple, where the RF current flows through the conductive element, creating an electric field of about zero within this volume, thereby preventing interference with temperature measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If RF current is flowed through a conventional conductive element to provide RF power to the RF electrode, then the RF electrode can receive sufficient RF power, but the electric field generated by the RF current distorts temperature measurements taken by thermocouples
Solution Approach 1:
The conductive element is segmented into multiple sections: an RF shielded section with conductive shielding material that surrounds the thermocouple, and non-shielded sections that allow RF current flow. This segmentation isolates the thermocouple from RF electric fields while maintaining RF power delivery capability through the unshielded portions of the conductive element.
Solution Approach 2:
A conductive shielding material acts as an intermediary between the RF current-carrying conductive element and the thermocouple. This shielding material creates a Faraday cage effect that blocks RF electric fields from reaching the thermocouple, thereby protecting the temperature measurement from RF interference while allowing RF power to be delivered through the conductive element.
2Reliability
If a conductive element is used to return RF current to ground, then the RF system can be completed, but the electric field from the RF current interferes with thermocouple readings
Solution Approach 1:
The conductive element serving as RF current return path is segmented into RF shielded and non-shielded sections. The shielded section contains the thermocouple and is surrounded by conductive shielding material, creating a protected zone where RF electric fields are excluded, thus maintaining accurate temperature measurements while the conductive element fulfills its RF current return function.
Solution Approach 2:
Different sections of the conductive element have different properties: the section containing the thermocouple is locally modified with conductive shielding material to create an RF-excluded zone, while other sections remain unshielded to allow RF current flow. This local quality change ensures that the thermocouple measurement zone is protected from RF interference while maintaining overall RF system functionality.
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 design allows for accurate temperature measurement of substrates during processing by isolating the electric field within the conductive element, ensuring that RF power can be received by the RF electrode without affecting the accuracy of thermocouple readings.
Implementation Method 1
a conductive element having an interior volume with the one or more conductive lines and the thermocouple disposed through the interior volume, the conductive element coupled to the RF electrode and having an electric field of about zero in the interior volume when RF current is flowed through the conductive element
Implementation Method 2
an RF electrode disposed in the substrate support proximate the substrate support surface to receive RF current from an RF source
Implementation Method 3
a heater disposed in the substrate support proximate the substrate support surface to provide heat to a substrate when disposed on the substrate support surface, the heater having one or more conductive lines to provide power to the heater
Implementation Method 4
a thermocouple disposed in the substrate support to measure the temperature of a substrate when disposed on the substrate support surface
Data Source
AI summary
Apparatus for processing a substrate are provided herein. In some embodiments, a substrate support includes a substrate support surface and a shaft; an RF electrode disposed in the substrate support proximate the substrate support surface to receive RF current from an RF source; a heater disposed proximate the substrate support surface to provide heat to a substrate when disposed on the substrate support surface, the heater having one or more conductive lines to provide power to the heater; a thermocouple to measure the temperature of a substrate when disposed on the substrate support surface; and a conductive element having an interior volume with the one or more conductive lines and the thermocouple disposed through the interior volume, the conductive element coupled to the RF electrode and having an electric field of about zero in the interior volume when RF current is flowed through the conductive element.