Multi-Unit Scanning for Precision Tool Positioning
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Solution Overview
Problem
Existing systems for positioning processing tools relative to workpieces in semiconductor production face challenges in achieving precise alignment due to measuring errors caused by deformations and misalignment of measuring standards, leading to significant position uncertainties during machining.
Innovation Solution
A system employing at least two scanning units with a defined offset on the first object to scan a scannable measuring standard, allowing for precise positioning of the processing tool relative to the workpiece by limiting scanning to small, spatially restricted regions, thereby minimizing errors from measuring standard deformations and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single scanning unit scans a long measuring standard to determine relative position, then the positioning system can cover the full range, but measuring errors increase due to deformations and thermal expansion of the measuring standard
Solution Approach 1:
The patent divides the measuring system into multiple scanning units (at least two) that scan different regions of the measuring standard simultaneously or sequentially. This segmentation allows the system to determine relative position over a large range while limiting the scanned region length for each unit, thereby reducing measuring errors caused by deformations and thermal expansion of any single measuring standard segment.
2Length of stationary object
If the scanning region is extended to cover large distances, then the positioning range increases, but measuring errors from deformations and thermal expansion increase
Solution Approach 1:
The patent employs multiple scanning units positioned at different locations along the measuring standard. Each scanning unit scans only a small, spatially restricted region, thereby maintaining high measurement precision. The combination of measurements from multiple scanning units achieves the desired large positioning range without sacrificing accuracy.
3Measurement precision
If thermal stabilization is implemented for the entire measuring standard, then measurement accuracy improves, but system complexity and energy consumption increase
Solution Approach 1:
The patent reduces the need for extensive thermal stabilization by segmenting the measuring system into multiple scanning units, each scanning only a small region. Since each scanned region is small, thermal stabilization requirements are reduced, leading to lower energy consumption and simplified thermal management while maintaining measurement accuracy.
4Measurement precision
If complex calibration procedures are performed to eliminate measuring errors, then positioning accuracy improves, but processing time and system complexity increase
Solution Approach 1:
The patent reduces calibration complexity and time by using multiple scanning units that each scan small, spatially restricted regions. The segmented approach inherently reduces measuring errors from deformations and thermal expansion, minimizing the need for complex calibration procedures while maintaining high positioning accuracy.
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 approach ensures highly precise positioning of the processing tool with reduced measuring errors, simplifies thermal stabilization, and eliminates the need for complex calibrations, resulting in improved accuracy and reduced position uncertainties during machining.
Implementation Method 1
Alignment sensor W is arranged as a microscope or camera equipped with an electronic image sensor, for example
Data Source
AI summary
In a system and a method for positioning a processing tool in relation to a workpiece, an object alignment mark and the workpiece are situated on a first object. In addition, a workpiece alignment mark is situated on the workpiece. The processing tool via which the object alignment mark is detectable is situated on a second object, which is disposed so as to be displaceable along at least one movement direction in relation to the first object. Furthermore, an alignment sensor is disposed thereon, with whose aid the object alignment mark and the workpiece alignment mark are detectable. In addition, a scannable measuring standard, which extends along the at least one movement direction, is disposed on the second object. At least two scanning units for scanning the measuring standard are situated on the first object in order to thereby determine the relative position between the first and the second object along the movement direction, the two scanning units having a defined offset.