Segmented Electrostatic Chuck for Warped Substrate Retention
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Solution Overview
Problem
Conventional electrostatic chucks struggle to efficiently attract and retain substrates with non-planar surfaces, particularly when portions of the substrate are excessively separated from the chuck surface, often requiring inefficient flattening processes that can damage the substrate.
Innovation Solution
An electrostatic chuck with segments of electrodes and actuators that adjust their position relative to the substrate to reduce the distance between the substrate and the chuck surface, applying a DC bias to generate sufficient electrostatic forces for secure retention without flattening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a DC bias is increased to attract the substrate to the ESC surface, then the electrostatic force increases, but portions of the substrate that are excessively separated cannot be attracted
Solution Approach 1:
The substrate support surface is divided into multiple independently controllable segments. Each segment can be individually actuated to adjust its position relative to the substrate, allowing localized compensation for substrate warpage or bowing. This segmentation enables the system to address distance variations across different regions of the substrate without requiring uniform high DC bias across the entire surface.
Solution Approach 2:
The substrate support segments are made dynamically adjustable through actuators that can change the position of each segment in real-time. This dynamic capability allows the system to adapt to the specific shape of the substrate (including warped or bowed substrates) by adjusting segment positions to minimize distances between the support surface and substrate across all regions, enabling reliable retention even when portions are initially excessively separated.
2Reliability
If conventional flattening processes are used to prepare the substrate, then the substrate can be attracted to the ESC surface, but the process is inefficient and may damage the substrate
Solution Approach 1:
The system performs preliminary positioning action by actuating the substrate support segments to optimal positions before applying the DC bias for substrate attraction. This preliminary adjustment of segment positions ensures that the distance between the support surface and substrate is minimized across all regions, creating ideal conditions for electrostatic attraction without requiring substrate flattening. This eliminates the need for time-consuming and potentially damaging flattening processes while ensuring reliable substrate retention.
3Force
If the substrate is warped or bowed in higher order mode shapes, then some portions contact the ESC surface while other portions are excessively separated, but increasing DC bias cannot attract the separated portions
Solution Approach 1:
The substrate support is divided into multiple independently controllable segments that can be individually positioned. This segmentation allows the system to accommodate complex warpage or bowing patterns (higher order mode shapes) by adjusting each segment's position to match the local substrate shape, thereby reducing distances across all regions without requiring uniform high DC bias.
Solution Approach 2:
Each segment of the substrate support can be independently actuated to provide localized compensation for substrate non-planarity. This local quality adjustment allows the system to adapt to varying substrate shapes across different regions, ensuring that each area has optimal distance for electrostatic attraction while accommodating the overall warped or bowed substrate shape.
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
Enables efficient chucking of non-planar substrates without damage, enhancing processing efficiency and avoiding substrate flattening-related issues.
Implementation Method 1
a DC bias is applied to pairs of electrodes disposed within the ESC. The applied DC bias generates an electrostatic force that attracts the substrate to a surface of the ESC
Data Source
AI summary
Embodiments of the disclosure include an electrostatic chuck (ESC). The ESC includes a substrate support including a first segment and a second segment that is laterally adjacent to the first segment. The first segment includes a first pair of electrodes. The second segment includes a second pair of electrodes. The first segment is to be displaced vertically relative to the second segment to accommodate a non-planar surface of a substrate.