Electrostatic Chuck Electrode Layout for Flattening Non-Flat Substrates
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Solution Overview
Problem
Conventional electrostatic chucks are limited in the clamp force they can generate due to wide gap electrode patterns, which restrict the area of the electrode and thus the clamp force, making it difficult to effectively hold and flatten non-flat substrates.
Innovation Solution
The electrostatic chuck design incorporates a symmetrical electrode pattern with narrow gaps between electrode phases, allowing for an increased electrode area and improved clamp force distribution. This design includes a dielectric layer that fills the gaps, enabling operation at higher voltage ranges and reducing the risk of electrical failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If wide gap electrode patterns are used in conventional electrostatic chucks, then the electrode area is reduced, but the clamp force generation capability is limited
Solution Approach 1:
The electrode pattern is divided into multiple phases (e.g., six phases) arranged symmetrically around the central axis. Each phase is separated by narrow gaps filled with dielectric material, allowing the electrode area to be maximized while maintaining electrical isolation between phases. This segmentation enables both large electrode area and high clamp force generation.
Solution Approach 2:
The electrode pattern employs asymmetrical phase arrangements where adjacent phases have different polarities. This asymmetrical configuration creates effective electrostatic forces across the entire electrode area, maximizing clamp force generation while utilizing the full available space.
2Area of stationary object
If narrow gaps between electrode phases are implemented, then the electrode area is increased, but the risk of electrical failure increases
Solution Approach 1:
A dielectric layer is introduced as an intermediary material filling the narrow gaps between adjacent electrode phases of opposite polarity. This dielectric layer prevents direct electrical contact and breakdown while allowing the gaps to remain narrow, thus maximizing electrode area without compromising electrical reliability.
Solution Approach 2:
The electrostatic chuck employs a composite structure combining conductive electrode material with dielectric filling material in the gaps. This composite approach allows narrow gaps to be maintained for maximum electrode area while the dielectric material provides electrical insulation to prevent failures.
3Force
If higher voltage is applied to generate sufficient clamp force for non-flat substrates, then the clamp force is improved, but the risk of electrical breakdown increases
Solution Approach 1:
The dielectric layer serves as a protective intermediary between the high-voltage electrode and the substrate, allowing higher voltages to be applied for increased clamp force while the dielectric material prevents electrical breakdown through its insulating properties.
Solution Approach 2:
The introduction of dielectric material changes the electrical parameters of the system, specifically increasing the breakdown voltage threshold. This allows the operating voltage to be increased for higher clamp force generation without proportionally increasing the risk of electrical breakdown.
4Force
If symmetrical electrode pattern with multiple phases is used, then the clamp force distribution is improved, but the device complexity increases
Solution Approach 1:
The electrode is segmented into multiple symmetrical phases that can be independently controlled. This segmentation improves clamp force distribution across the substrate surface, particularly for non-flat substrates, while the modular symmetrical design actually simplifies the overall pattern configuration.
Solution Approach 2:
The symmetrical multi-phase electrode pattern serves multiple functions: it provides uniform clamp force distribution, enables independent phase control for complex substrate geometries, and maintains rotational symmetry for simplified manufacturing and alignment.
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 enhanced electrostatic chuck design achieves higher clamp forces, allowing for the effective flattening of non-flat substrates and operation at higher backside gas pressures, which improves cooling efficiency and substrate handling during manufacturing processes.
Implementation Method 1
the back side of a substrate, such as bare wafer or an in-process semiconductor wafer, is held to the face of the electrostatic chuck by an electrostatic force sometimes referred to as a clamp force
Implementation Method 2
the electrode is configured to generate an electrostatic force sufficient to at least partially flatten a non-flat substrate
Data Source
AI summary
An electrostatic chuck includes an electrode and a dielectric layer. When a voltage is applied to the electrode, the electrode is configured to generate an electrostatic force sufficient to flatten a non-flat substrate. The voltage applied to the electrode generates the electrostatic force sufficient to flatten the non-flat substrate such that a surface of the flattened substrate is substantially in contact with a surface of the electrostatic chuck.