Three-Point Substrate Centering for Precise Eccentricity Alignment
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in aligning the center of a disk-shaped substrate with the substrate support due to misalignment, which affects processing quality, and existing centering devices are limited by size and design restrictions.
Innovation Solution
A centering device with three contact members that move in specific horizontal directions to align the substrate center with the support, utilizing a controller to adjust substrate posture and equalize distances from the support center, allowing for efficient alignment with minimal force and reduced mechanical restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If three contact members are reciprocally moved on axis lines radially extending from the center axis of the substrate support, then the centering operation can be performed, but the device size enlarges
Solution Approach 1:
The centering device divides the substrate into multiple sectors, with each contact member responsible for centering a specific sector. This segmentation allows each contact member to operate independently on a smaller scale, reducing the overall device size while maintaining effective centering coverage across the entire substrate surface.
Solution Approach 2:
The contact members are arranged in a radial pattern extending from the center axis of the substrate support, utilizing radial dimensionality rather than linear arrangement. This radial configuration allows three contact members to cover the entire substrate perimeter effectively, reducing device size compared to linear arrangements.
2Manufacturing precision
If the second and third contact members are arranged to handle substrate movement in orthogonal direction, then centering accuracy improves, but the degree of design freedom is restricted
Solution Approach 1:
The second and third contact members are positioned asymmetrically relative to the first contact member, with their axis lines forming specific angles with the radial direction. This asymmetric arrangement allows the contact members to handle both radial and orthogonal substrate movement components, achieving accurate centering while maintaining design flexibility.
Solution Approach 2:
The contact members are designed with movable axes that can dynamically adjust their orientation. The axis lines of the second and third contact members extend at angles different from the radial direction, allowing dynamic adaptation to substrate movement in various directions, thereby improving centering accuracy without restricting design freedom.
Data Source
AI summary
A substrate supported on a substrate support is surrounded by a first contact member located at a first reference position, a second contact member located at a second reference position and a third contact member located at a third reference position in the horizontal plane. These three contact members gradually approach the substrate while keeping distances from a center of the substrate support equal by repeating the minute movements. The substrate posture is so adjusted that the direction of eccentricity is parallel to the virtual line prior to the start of the movements of the contact members. In the invention, the substrate posture is so adjusted that the direction of eccentricity is parallel to the virtual line prior to the above centering of the substrate.