Position Measurement Device with Extracted Illumination and Protective Gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current devices for measuring structures on masks or substrates face challenges in achieving high resolution due to the limitations of traditional light sources, particularly at shorter wavelengths, and struggle with heat generation from illumination apparatuses, which can affect measurement accuracy and the service life of optical components.
Innovation Solution
A device utilizing a laser interferometer system with an excimer laser or frequency-multiplied solid-state laser for illumination, combined with optical elements like high-resolution microscope objectives and a protective gas environment to enhance measurement precision and extend the service life of optical components, while minimizing heat influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional light sources are used for illumination, then the device can operate at various wavelengths, but measurement resolution is insufficient for smaller structures
Solution Approach 1:
The patent changes the wavelength parameter of the illumination light by using different light sources (mercury-xenon lamp for 365 nm, excimer laser for 248 nm, frequency-multiplied solid-state laser for other wavelengths) to match the required measurement resolution for different structure sizes
2Measurement precision
If high-power illumination apparatus is used to improve measurement signal quality, then measurement precision improves, but heat generation increases affecting measurement accuracy and component service life
Solution Approach 1:
The patent extracts the illumination apparatus from the measurement environment and positions it outside the climate chamber, allowing the light to be directed into the chamber through a window. This separates the heat-generating component from the temperature-sensitive measurement zone
Solution Approach 2:
The patent introduces a climate chamber as an intermediary between the illumination apparatus and the measurement environment. The chamber maintains controlled temperature and protects optical components from heat while allowing light transmission through its window
3Measurement precision
If shorter wavelengths are used to improve resolution for smaller structures, then measurement precision improves, but suitable light sources with sufficient intensity become unavailable
Solution Approach 1:
The patent changes the light source type to match the required wavelength and intensity parameters. For 248 nm illumination, an excimer laser is used instead of conventional lamps, and for other wavelengths, frequency-multiplied solid-state lasers are employed, ensuring sufficient intensity at each specific wavelength
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
Enables precise measurement of smaller structures with improved resolution and reduced heat impact, extending the service life of optical components and maintaining measurement accuracy across various wavelengths.
Implementation Method 1
at least one laser interferometer for determining a positional displacement of the measuring table in the plane
Implementation Method 2
A device utilizing a laser interferometer system with an excimer laser or frequency-multiplied solid-state laser for illumination
Implementation Method 3
optical elements like high-resolution microscope objectives
Data Source
AI summary
A device for determining the position of a structure (3) on an object (2) in relation to a coordinate system is disclosed. The object (2) is placed on a measuring table (20) which is movable in one plane (25a), wherein a block (25) defines the plane (25a). At least one optical arrangement (40, 50) is provided for transmitted light illumination and/or reflected light illumination. The optical arrangement (40, 50) comprises an illumination apparatus (41, 51) for reflected light illumination and/or transmitted light illumination and at least one first or second optical element (9a, 9b), wherein at least part of the at least one optical element (9a, 9b) extends into the space (110) between the block (25) and an optical system support (100). The block (25) and/or the optical system support (100) separates the illumination apparatus (41, 51) spatially from the plane (25a) in which the measuring table (20) is movable.