Mark Field for Substrate Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining the XY positions of structural features on substrates require expensive and complex electronic-mechanical systems, which are sensitive to temperature fluctuations and necessitate precise tracking of the substrate holder's position, often using interferometers, to account for thermal expansion and ensure accurate positioning.
Innovation Solution
A device and method utilizing a mark field with encoded position marks that allow for precise determination of XY positions independently of the substrate holder's movement, eliminating the need for a spatially fixed reference system by associating structural features with position marks on a separate surface, enabling precise positioning without tracking the substrate holder's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If expensive optical systems and interferometers are used to track substrate holder position, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent creates a virtual copy of the substrate holder's position and orientation by using markers attached to it and tracking their positions in the coordinate system of the fixed camera. This allows the system to determine substrate holder position without complex mechanical tracking systems, resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The patent introduces markers as intermediary objects that bridge the substrate holder and the fixed camera. These markers carry position information that can be read by the camera, enabling position determination without direct mechanical coupling or complex tracking infrastructure between the substrate holder and measurement system
2Measurement precision
If the substrate holder position is continuously tracked over several centimeters, then measurement precision is maintained, but thermal expansion effects increase due to temperature fluctuations
Solution Approach 1:
The patent transitions from tracking the substrate holder's position in physical space using mechanical systems to determining position through optical detection of markers in a coordinate system. This dimensional shift from mechanical tracking to optical measurement reduces sensitivity to thermal expansion over the travel distance of the substrate holder
3Measurement precision
If a fixed coordinate system is used to specify substrate holder position, then measurement precision is improved, but device complexity and cost increase due to required infrastructure
Solution Approach 1:
The patent merges the coordinate system definition with the markers themselves. The markers are defined in the coordinate system of the fixed camera, combining the reference frame and the measurement targets into a single integrated system. This eliminates the need for separate, complex infrastructure to establish and maintain a fixed coordinate system
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a mark field (4), comprising at least two location marks (2) having information about the location of the location mark (2) in question and at least one position mark (3), which is or can be associated with one of the location marks (2). The invention further relates to a device for determining X-Y-positions of structure features (11c) of structures (11) arranged on a substrate (7), wherein the X-Y-positions can be determined relative to the mark field (4), which is fixed in relation to the substrate. Furthermore, the invention relates to a corresponding method.