Electrostatic Chuck Electrode Layout for Low-Frequency Bias Efficiency
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Solution Overview
Problem
In plasma processing apparatuses, the series voltage component due to capacitance between the base and heater electrode in an electrostatic chuck does not contribute to improving the substrate voltage (Vpp) and can consume unnecessary power, leading to high voltage requirements for bias power, especially at low frequencies, which affects efficiency.
Innovation Solution
The substrate support system includes an electrostatic chuck with a first electrode for substrate attraction and a second electrode for bias power, where the second electrode is positioned closer to the first support surface than the base, allowing for efficient bias power supply and reducing unnecessary voltage components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If bias power is supplied to the base through the heater electrode in conventional electrostatic chucks, then substrate processing is enabled, but unnecessary voltage components are generated due to capacitance between base and heater electrode, consuming extra power and requiring higher voltage especially at low frequencies
Solution Approach 1:
The invention divides the electrode structure into separate components: a first electrode for substrate attraction and a second electrode for bias power supply. This segmentation allows independent optimization of each electrode's function, eliminating the unnecessary voltage component caused by capacitance between base and heater electrode that occurs when bias power is supplied through the base in conventional designs.
Solution Approach 2:
The invention extracts the bias power supply function from the base structure and assigns it to a dedicated second electrode. By taking out the bias power supply path from the base-heater electrode connection, the patent eliminates the parasitic capacitance effect between base and heater electrode that causes unnecessary power consumption and voltage requirements.
2Productivity
If the second electrode is positioned close to the first support surface, then bias power efficiency is improved, but the electrode arrangement becomes more complex
Solution Approach 1:
The invention implements a nested electrode arrangement where the second electrode (for bias power) is positioned within the electrostatic chuck structure, closer to the first support surface than the base. This nesting allows the second electrode to be integrated into the existing electrostatic chuck assembly without requiring separate external structures, thereby improving bias power efficiency while controlling complexity through clever spatial integration.
Solution Approach 2:
The patent utilizes the vertical dimension within the electrostatic chuck structure to position the second electrode at an optimized height closer to the first support surface. By arranging electrodes in the vertical dimension rather than only horizontal planes, the invention achieves improved bias power efficiency through better electric field coupling while maintaining a compact overall structure.
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 improves the efficiency of bias power on the low frequency side by reducing unnecessary voltage and power consumption, while maintaining effective substrate voltage, thereby enhancing etching rates and reducing electrical stress.
Implementation Method 1
an electrostatic chuck provided with a first support surface for supporting a substrate, provided with a first electrode and a second electrode which are arranged in the electrostatic chuck sequentially from the first support surface
Implementation Method 2
bias power is supplied to the second electrode... improves the efficiency of bias power on the low frequency side... enhancing etching rates
Data Source
AI summary
A substrate support is arranged in a processing container. The substrate support includes an electrostatic chuck provided with a first support surface for supporting a substrate, provided with a first electrode and a second electrode which are arranged in the electrostatic chuck sequentially from the first support surface, and made of a dielectric material, and a base configured to support the electrostatic chuck. The second electrode is arranged at a position having a distance to the first support surface that is equal to or less than a distance to the base. A voltage for attracting the substrate is applied to the first electrode and bias power is supplied to the second electrode.