Optical Device Alignment Using Mechanical Zero Position
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Solution Overview
Problem
In EUV lithography apparatuses, aligning reflective optical units like facet mirrors is complex due to mounting and manufacturing tolerances, requiring significant adjusting forces and reducing the tiltable angular range, which complicates achieving the optical zero position without deflecting the movable components.
Innovation Solution
A method involving a mechanical operative connection between a movable component and an optical component, where the movable component is fixed in a mechanically defined position, optically measured, and adjusted to attain simultaneous optical and mechanical zero positions, minimizing the need for adjusting forces and maximizing the tiltable range, using an electromagnetic actuator and a spacer element to alter the geometry and position of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If facet mirrors are aligned using conventional methods with electromagnetic actuators, then the optical components can be adjusted, but significant adjusting forces are required and the tiltable angular range is reduced due to mounting and manufacturing tolerances
Solution Approach 1:
The patent applies preliminary action by defining a mechanical zero position for the movable component before optical measurement. The movable component is fixed in this mechanically defined position relative to the reference component, and then optically measured to determine the deviation from the optical zero position. This preliminary mechanical positioning simplifies the subsequent adjustment process by providing a known reference point.
Solution Approach 2:
The patent replaces complex mechanical alignment procedures with an optical measurement system. Instead of using complex mechanical fixtures and manual alignment tools, the invention uses optical measurement to detect the position of the optical component and determine the deviation from the optical zero position, thereby simplifying the alignment process.
2Manufacturing precision
If adjusting forces are applied to achieve optical zero position, then alignment can be achieved, but the tiltable angular range of the movable component is reduced
Solution Approach 1:
The patent defines a mechanical zero position for the movable component and fixes it in this position before optical measurement. This preliminary mechanical positioning allows the system to determine the deviation from the optical zero position without applying adjusting forces that would reduce the tiltable angular range.
Solution Approach 2:
The patent changes the reference parameter from a mechanical reference to an optical reference. By using optical measurement to detect the position of the optical component and determine the deviation from the optical zero position, the system can achieve precise alignment without the mechanical constraints that limit tiltable angular range.
3Reliability
If conventional alignment methods are used, then mounting tolerances can be accommodated, but the alignment process becomes complex and energy consumption increases
Solution Approach 1:
The patent replaces complex mechanical alignment procedures with an optical measurement system. The optical measurement device detects the position of the optical component and determines the deviation from the optical zero position, eliminating the need for complex mechanical alignment tools and reducing energy consumption.
Solution Approach 2:
The system uses the optical component itself as the measurement target. The optical measurement device measures the optical component directly to determine its position and deviation from the optical zero position, eliminating the need for separate alignment fixtures or reference objects and reducing overall system 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 method allows for simultaneous attainment of optical and mechanical zero positions without applying adjusting forces, maximizing the tiltable range and minimizing energy consumption, thereby simplifying the alignment process and improving the operational efficiency of the optical device.
Implementation Method 1
an electromagnetic actuator actuates a magnet element provided on a drive plunger
Implementation Method 2
optically measuring the optical component in order to obtain an optical measurement result
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A method for adjusting an optical device (200), in particular for a lithography apparatus (100A, 100B), comprising a movable component (326, 700), a reference component (318, 346, 702) and an optical component (202, 706), wherein the movable component (326, 700) is connected by a mechanical operative connection (328, 704) to the optical component (202, 706), comprising the following steps: a) fixing (S1) the movable component (326, 700) in a mechanically defined position (NP) with respect to the reference component (318, 346, 702), b) optically measuring (S2) the optical component (202, 706) in order to obtain an optical measurement result (OM), and c) adjusting (S8) the optical device (200) depending on the optical measurement result (OM).