Piezo Actuator Electrode Segmentation for Lithography Flatness
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Solution Overview
Problem
Current piezo actuators in lithographic apparatuses face limitations in achieving accurate substrate flatness and in-plane deformation control, especially when multiple degrees of freedom are required, due to the Poisson ratio of piezo electric materials and restricted available volume.
Innovation Solution
A substrate support system incorporating a piezo actuator with a first surface and a second surface, featuring a first pair of electrodes divided into parts to provide different voltages or charges, allowing for precise elongation and shearing of the piezo material to correct substrate shape and alignment, while an amplifier provides these voltages or charges to optimize movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple piezo actuators are put together to actuate in multiple degrees of freedom, then the actuator can achieve multi-directional movement, but the device size becomes large which is undesired in restricted volume situations
Solution Approach 1:
The patent combines multiple piezo actuators (first translating piezo actuator and first shear piezo actuator) into a single integrated actuator assembly that operates together to provide multi-degree of freedom movement, eliminating the need for separate actuators for each degree of freedom and reducing overall volume
Solution Approach 2:
The integrated piezo actuator assembly performs multiple functions simultaneously - it provides both translation and shearing movements through a unified structure, allowing a single device to handle multiple degrees of freedom that would traditionally require separate specialized actuators
2Adaptability or versatility
If multiple electrodes are applied on piezo electric material to enable swivel movement in two degrees of freedom, then the actuator can achieve multi-directional control, but the accuracy is limited due to the Poisson ratio of the piezo electric material
Solution Approach 1:
The piezo electric material is divided into multiple segments with separate electrodes (first pair of electrodes and second pair of electrodes) that can be controlled independently, allowing precise control of different deformation modes (translation and shearing) without the accuracy limitations of unified multi-electrode designs
Solution Approach 2:
The patent employs dynamic control of multiple piezo actuators with independent voltage control, allowing the system to adaptively adjust the contribution of each actuator to achieve desired movement while compensating for Poisson ratio effects and maintaining high positioning accuracy
3Shape
If piezo actuators are used to control substrate flatness, then the substrate shape can be adjusted, but in-plane deformation control is insufficient for accurate multi-layer pattern projection
Solution Approach 1:
The substrate support system uses multiple independently controlled piezo actuators (including both translating and shearing types) distributed across the substrate, enabling separate control of out-of-plane (flatness) and in-plane (deformation) parameters through segmented actuation zones
Solution Approach 2:
The system changes multiple parameters simultaneously - both the vertical position (flatness) and lateral position (in-plane deformation) of substrate regions - by independently adjusting the voltage applied to different piezo actuators, thereby achieving comprehensive substrate shape control required for accurate multi-layer pattern projection
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 solution enhances the accuracy of substrate flatness and in-plane deformation control, enabling precise projection of patterns on multiple layers by allowing independent control of the piezo actuator's movement in multiple degrees of freedom, thereby improving the overall precision of the lithographic process.
Implementation Method 1
Piezo actuators comprise piezo electric material that deforms when a voltage or an electrical charge is applied over the piezo electric material via electrodes
Implementation Method 2
the first electrode is divided into at least two parts... the amplifier is arranged to provide one of the parts with a first voltage or charge and the other one of the parts with a second voltage or charge
Data Source
AI summary
The invention provides a substrate support arranged to support a substrate, comprising piezo a actuator, further comprising a first pair of electrodes, a second pair of electrodes and a piezo material having a first surface and a second surface. The first surface is arranged along a first direction and second direction. The first pair of electrodes comprises a first electrode arranged on the first surface and a second electrode arranged on the second surface. The second pair of electrodes is arranged to shear the piezo material. The first pair of electrodes is arranged to elongate the piezo material in a third direction perpendicular to the first direction and second direction. The first electrode is divided into at least two parts and is arranged to rotate the first surface and the second surface relatively to each other about the first direction wherein the piezo actuator is arranged to support the substrate.