Electrostatic Chuck With Surface Burls And Segmented Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrostatic holding apparatuses for components like silicon wafers suffer from sensitivity to unwanted particles, deformation, and poor thermal and mechanical coupling due to embedded electrodes, leading to increased clamping voltage risks and planarity issues.
Innovation Solution
The holding apparatus features a base body with conductive Si-based ceramic plates and insulating layers, where electrodes are placed on burls to minimize distance and maximize height, reducing particle sensitivity and deformation, with improved thermal and mechanical stability, and a simplified production process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If electrodes are embedded between plate-type elements, then the electrostatic holding apparatus can generate holding forces, but the burls must be kept at minimal height which reduces mechanical coupling and thermal coupling with the component
Solution Approach 1:
The electrode device is segmented into multiple electrodes arranged in a matrix pattern on the upper surface of the first plate, rather than using a single embedded electrode structure. This segmentation allows for better distribution of electrostatic forces while maintaining adequate burl height for mechanical coupling.
Solution Approach 2:
The electrodes are positioned on the upper surface of the first plate in a two-dimensional matrix arrangement, transitioning from the conventional embedded three-dimensional structure. This dimensional change optimizes both the electrostatic holding force generation and the mechanical coupling through properly sized burls.
2Force
If electrodes are embedded between plate-type elements, then the electrostatic holding apparatus can generate holding forces, but the apparatus becomes sensitive to unwanted particles
Solution Approach 1:
The electrodes are extracted from the embedded configuration and positioned on the upper surface of the first plate. This extraction eliminates the particle-trapping issue associated with embedded electrodes while maintaining effective electrostatic holding force generation through the surface-mounted electrode matrix.
3Object-affected harmful factors
If burls are kept at minimal height to reduce particle sensitivity, then particle sensitivity is reduced, but thermal coupling and mechanical stability are impaired
Solution Approach 1:
The burls are designed with optimized local dimensions and material properties (electrically conductive, Si-based ceramic) to provide adequate height for thermal coupling and mechanical stability. The local quality of the burl structure is enhanced to simultaneously achieve particle sensitivity reduction and improved thermal contact with the component.
4Reliability
If conventional embedded electrode structures are used, then the apparatus can function, but the production process is complex and time-consuming
Solution Approach 1:
The electrode structure is merged with the upper surface of the first plate, eliminating the need for separate embedding steps. The electrodes are integrated into the plate structure, simplifying the production process while maintaining reliable electrostatic holding functionality.
Solution Approach 2:
The electrodes are pre-positioned on the upper surface of the first plate during plate fabrication, rather than being embedded after assembly. This preliminary action simplifies the overall production process and reduces manufacturing complexity.
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 design enhances mechanical and thermal stability, reduces particle sensitivity, and allows for lower clamping voltage without compromising holding force, while simplifying production and reducing deformation risks.
Implementation Method 1
receiving a clamping voltage
Implementation Method 2
thermal coupling with the component to be held is improved
Data Source
AI summary
Holding apparatus (100) for electrostatically holding component (1), (e.g., a silicon wafer), includes base body (10) composed of first and second plates (11A,12), the first plate being arranged on upper side (10A) of base body (10) and second plate (12) carrying first plate (11A), and second plate (12) being an electrically insulating material, a plurality of projecting, upper burls (13A) arranged on upper side (10A) and forming a support surface for component (1), and first electrode device (20A) having first electrodes (21A) arranged on upper side (10A) for receiving a clamping voltage, wherein first plate (11A) is produced from electrically conductive, Si-based ceramic and carries upper plate insulating layer (14A) which covers upper side (10A), having upper burls (13A), and the first electrodes (21A) include electrode layers arranged on upper burls (13A) and each carry upper electrode insulating layer (15A). A method for producing the holding apparatus is also described.