Bipolar Electrostatic Chuck Layout for High-Temperature RF Uniformity
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Solution Overview
Problem
Conventional substrate support systems in semiconductor manufacturing face challenges such as substrate movement during processing, increased likelihood of DC discharge at high temperatures, and non-uniform plasma deposition due to monopolar or semicircular electrode configurations, leading to arcing and damage to chamber components.
Innovation Solution
The implementation of substrate support assemblies with bipolar chucking capabilities, featuring a first and second bipolar electrode embedded within the electrostatic chuck body, coupled with RF power supplies and floating DC power supplies, which prevent arcing by ensuring gapless RF electrode coverage and maintaining uniform RF fields across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If monopolar or semicircular electrode configurations are used, then substrate support is provided, but substrate movement occurs and plasma deposition is non-uniform
Solution Approach 1:
The electrode is divided into multiple segments (first electrode segment, second electrode segment, third electrode segment) arranged in a specific pattern. This segmentation allows independent control of different regions, enabling uniform plasma deposition across the substrate while maintaining substrate stability through the distributed electrode configuration.
Solution Approach 2:
The electrode segments are arranged asymmetrically with varying positions and orientations. The first electrode segment has a different configuration compared to the second and third segments, creating an asymmetric field distribution that compensates for edge effects and achieves uniform plasma deposition across the substrate surface.
2Temperature
If high temperatures are used for substrate processing, then material formation and removal processes are improved, but DC discharge and arcing increase
Solution Approach 1:
The system applies periodic RF power to the electrode segments rather than continuous DC power. This periodic action prevents sustained DC discharge and arcing that occur at high temperatures, while still enabling effective plasma generation for material formation and removal processes.
Solution Approach 2:
The system changes the electrical parameter from DC to RF power supply, and adjusts the power level dynamically. This parameter change allows operation at high substrate temperatures without the harmful DC discharge effects, as RF power does not create the same arcing conditions as DC power at elevated temperatures.
3Productivity
If the pedestal is used for both heat generation and plasma generation, then operational efficiency is improved, but interference effects occur
Solution Approach 1:
The pedestal functionality is segmented into separate heating elements and electrode segments. This segmentation allows independent control of heat generation and plasma generation functions, eliminating interference effects while maintaining operational efficiency through coordinated operation of the separated functional elements.
Solution Approach 2:
Different regions of the pedestal are assigned different functions: some regions contain heating elements for thermal control, while other regions contain electrode segments for plasma generation. This local differentiation of function eliminates interference between heating and plasma generation while maintaining overall operational efficiency.
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
These assemblies provide stable substrate support during high-temperature operations, prevent DC discharge, and ensure uniform plasma deposition across the wafer, including edge regions, thereby enhancing processing precision and reducing damage to chamber components.
Implementation Method 1
An RF power supply may be coupled with both of the first bipolar electrode and the second bipolar electrode
Implementation Method 2
a first floating DC power supply coupled with the first bipolar electrode. The substrate support assemblies may include a second floating DC power supply coupled with the second bipolar electrode
Data Source
AI summary
Exemplary support assemblies may include an electrostatic chuck body defining a support surface that defines a substrate seat. The assemblies may include a support stem coupled with the chuck body. The assemblies may include a heater embedded within the chuck body. The assemblies may include a first bipolar electrode embedded within the electrostatic chuck body between the heater and support surface. The assemblies may include a second bipolar electrode embedded within the chuck body between the heater and support surface. Peripheral edges of one or both of the first and second bipolar electrodes may extend beyond an outer periphery of the seat. The assemblies may include an RF power supply coupled with the first and second bipolar electrodes. The assemblies may include a first floating DC power supply coupled with the first bipolar electrode. The assemblies may include a second floating DC power supply coupled with the second bipolar electrode.