Compact Lithography Stage Design with Eccentric Cam Drive
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Solution Overview
Problem
Lithography systems require high-precision target positioning devices with a large footprint, which is disadvantageous in clean rooms due to space constraints and can be affected by electromagnetic dispersion fields from actuators.
Innovation Solution
A target positioning device with a compact design using two X-stage bases on a common base plate, connected via a Y-beam and flexible coupling, and driven by motors with eccentric cams or cranks, reducing the footprint and minimizing electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If highly accurate, rigid and robust stages are used to achieve high precision positioning, then positioning precision is improved, but the footprint and space requirement increase
Solution Approach 1:
The stage is divided into two separate X-stage bases (first and second X-stage bases) that are arranged on top of a common base plate. Each X-stage base carries an X-stage carriage independently. This segmentation allows the system to achieve the required positioning precision through coordinated movement of multiple smaller, more compact units rather than requiring a single large rigid stage structure.
Solution Approach 2:
The Y-beam bridges the space between the X-stage carriages in the vertical dimension, connecting them via flexible couplings. This three-dimensional arrangement allows the X-stage carriages to be positioned closer together horizontally while maintaining structural integrity through the vertical Y-beam connection, thereby reducing the overall footprint while preserving positioning accuracy.
2Object-affected harmful factors
If actuators are arranged remote from the stage to reduce electromagnetic interference, then electromagnetic interference is reduced, but the footprint increases
Solution Approach 1:
The motors are extracted from the traditional remote positioning and arranged substantially below the stage structure. By integrating the actuators into the base plate area rather than positioning them remotely, the system eliminates electromagnetic interference with the charged particle beam while maintaining a compact footprint, as the motors occupy space that would otherwise be part of the stage's mechanical structure.
3Area of stationary object
If motors are arranged below the stage to reduce footprint, then footprint is reduced, but access for maintenance and operation becomes more difficult
Solution Approach 1:
The motors are merged with the base plate structure, arranged substantially below the stage but integrated into the overall mechanical assembly. This integration allows for compact positioning while maintaining accessible service points on the exterior of the base plate, enabling maintenance personnel to access and service the motors without requiring disassembly of the entire stage structure.
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
The compact design reduces the footprint and minimizes electromagnetic interference, allowing for high-precision target positioning with reduced space requirements and lower costs, while using non-vacuum-compatible motors and encoders, and providing additional freedom for stage movement to correct deviations.
Implementation Method 1
each motor of said two motors is coupled to an eccentric cam or crank which is connected to the corresponding X-stage carriage via a crank shaft
Data Source
AI summary
A target positioning device, in particular for a lithography system, comprising a carrier for carrying a target, and a stage for carrying and moving the carrier along a first direction (X). The stage comprising two X-stage bases, both arranged on top of a common base plate, each X-stage base carries an X-stage carriage, and a Y-beam comprising a Y-stage for carrying said carrier and moving the carrier said carrier in a second direction (Y). The Y-beam bridges the space between the X-stage carriages and is connected to the X-stage carriages via a flexible coupling. The device further comprises two motors each for driving a corresponding X-stage carriage along its corresponding X-stage base. The two motors are arranged at least substantially below the stage. Each motor of said two motors is coupled to an eccentric cam or crank which is connected to the corresponding X-stage carriage via a crank shaft.