Stage Positioning Measurement with Merged 1D and 2D Encoders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In photolithography processes, especially in semiconductor and display device manufacturing, the precision of stage positioning is compromised due to errors from driving devices and environmental factors, leading to quality deterioration in thin film manufacturing and testing.
Innovation Solution
A stage transferring device equipped with a stage position measuring system that includes one-dimensional and two-dimensional encoders, laser interferometers, and reading heads to accurately measure and control the position of the moving stage in the x-y plane, using overlapping scales and encoders to set and reset coordinates, and minimize errors caused by external influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single encoding device (either 1D scale or 2D encoder) is used to measure stage position, then the device complexity is low, but the measurement precision deteriorates due to errors from driving devices and environmental factors
Solution Approach 1:
The patent combines a one-dimensional scale reading head and a two-dimensional encoder reading head into a single integrated reading head assembly. This merged structure allows simultaneous measurement of y-axis position (via 1D scale) and x-y coordinates (via 2D encoder), enabling cross-validation of measurements and compensation for errors from driving devices and environmental factors, thereby improving measurement precision without proportionally increasing device complexity
Solution Approach 2:
The patent implements a feedback mechanism where the y-axis coordinate measured by the 1D scale reading head is used to verify and correct the y-axis coordinate measured by the 2D encoder reading head. The control device compares both measurements and uses the 1D scale data as a reference to compensate for errors, creating a closed-loop feedback system that continuously improves measurement accuracy
2Measurement precision
If multiple encoding devices are used to improve measurement precision, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The integrated reading head assembly is designed to perform multiple functions: the 1D scale reading head measures y-axis position while the 2D encoder reading head measures both x-axis and y-axis coordinates. This multi-functional design allows a single reading head assembly to provide redundant measurement capabilities, improving precision through cross-validation while avoiding the need for separate independent measurement systems that would increase complexity
3Manufacturing precision
If traditional single-axis stage movement is used, then the device complexity is low, but the manufacturing precision deteriorates due to cumulative errors in photolithography processes
Solution Approach 1:
The patent transitions from traditional single-axis (1D) stage positioning to two-dimensional (2D) stage positioning by integrating both 1D scale and 2D encoder measurement systems. This dimensional expansion allows the system to measure and control both x-axis and y-axis positions simultaneously, eliminating cumulative errors that occur in sequential single-axis movement and thereby improving thin film pattern precision in photolithography processes
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
Enhances the precision of stage positioning, reducing measurement errors and improving the reliability of manufactured or tested products by accurately controlling the stage position, even during rapid movements.
Implementation Method 1
a one-dimensional scale reading head which is configured to overlap the one-dimensional scale, irradiate a measuring beam to the overlapped one-dimensional scale and measure a 1D y-axis coordinate of the transferring stage
Implementation Method 2
a two-dimensional encoder reading head which is configured to overlap the two-dimensional encoder, irradiate a measuring beam to the overlapped two-dimensional encoder and measure a 2D x-axis coordinate and a 2D y-axis coordinate of the transferring stage
Data Source
AI summary
A stage transferring device invention includes: a transferring stage upon which an object is mounted and which transfers the object in an x-y plane; and a stage position measuring device. The stage position measuring device includes a one-dimensional scale on the transferring stage; a one-dimensional scale reading head which is configured to overlap the one-dimensional scale, irradiate a measuring beam to the overlapped one-dimensional scale and measure a 1D y-axis coordinate of the transferring stage; a two-dimensional encoder on the transferring stage; and a two-dimensional encoder reading head which is configured to overlap the two-dimensional encoder, irradiate a measuring beam to the overlapped two-dimensional encoder and measure a 2D x-axis coordinate and a 2D y-axis coordinate of the transferring stage.