Interference Exposure Device with Angular Adjustment for Uniform Stitching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional interference lithography techniques face challenges in achieving uniform pattern stitching over large areas due to wave-front distortions and phase aberrations, leading to inconsistencies and stitching errors in periodic patterning of nanometer-scaled features.
Innovation Solution
An interference exposure apparatus and method that includes a light source, a light homogenizer-collimator, an interference unit with movable gratings, and a measuring system to adjust the exposure position based on angular deviations, ensuring high-uniformity pattern stitching across large areas by compensating for non-zero angles between the interference unit and the substrate movement direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If spherical-wave-based interference lithography is used to achieve large area exposure, then the exposure area is increased, but wave-front distortions cause inconsistency in feature distribution between center and periphery
Solution Approach 1:
The patent divides the exposure process into multiple sub-fields, exposing the substrate in a step-by-step manner rather than attempting to expose the entire large area in a single step. This segmentation approach allows each sub-field to be exposed with controlled wave-front characteristics, maintaining feature distribution uniformity across the entire large area while avoiding the peripheral distortions inherent in single-step large-area spherical-wave exposure
Solution Approach 2:
The patent employs dynamic adjustment of the optical system parameters and substrate positioning during the exposure process. By continuously adjusting the wave-front correction parameters and repositioning the substrate between sub-field exposures, the system adapts to maintain optimal feature distribution uniformity across different areas of the large substrate, preventing the center-periphery inconsistency that occurs in static spherical-wave systems
2Manufacturing precision
If plane wave interference lithography is used to reduce wave-front distortions, then feature distribution uniformity is improved, but phase aberrations from optical members and environmental media affect uniformity in large exposure fields
Solution Approach 1:
The patent introduces wave-front correction elements as intermediary components in the optical path between the plane wave source and the substrate. These correction elements actively compensate for phase aberrations introduced by optical members and environmental media, allowing large exposure areas to be achieved while maintaining feature distribution uniformity that would otherwise be degraded by the accumulated phase errors across the large field
3Manufacturing precision
If exposure field is reduced to alleviate phase aberrations, then feature distribution uniformity is improved, but stitching errors occur across the whole exposure field due to angle between interference beams and stage movement
Solution Approach 1:
The patent implements feedback control mechanisms that monitor the actual positions and orientations of the interference beams relative to the substrate stage movement. This feedback information is used to dynamically adjust the beam angles and positioning parameters, ensuring that stitching between adjacent sub-fields is accurate while maintaining feature distribution uniformity within each field. The feedback loop prevents stitching errors that would otherwise result from angular misalignment
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 solution enables high-uniformity pattern stitching in large areas with reduced stitching errors, allowing for the printing of a variety of periodic pattern designs by accurately aligning and positioning the coherent light beams on the substrate.
Implementation Method 1
a light homogenizer-collimator for homogenizing and collimating the exposure light beam emanating from the light source
Implementation Method 2
a light homogenizer-collimator for homogenizing and collimating the exposure light beam emanating from the light source
Implementation Method 3
an interference unit including at least two gratings for converting the exposure light beam into at least two coherent light beams
Implementation Method 4
the interference unit being movable in a vertical direction to make the at least two coherent light beams converge on a surface of a substrate to form an interference exposure pattern
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An interference exposure device, including: a light source (100) for providing an exposure light beam; a light homogenizer-collimator (200) for homogenizing and collimating the exposure light beam; an interference unit (300) including at least two gratings (303) for converting the exposure light beam into at least two coherent light beams and making the coherent light beams converge on a substrate surface to form thereon an interference exposure pattern, the gratings (303) each having a period and being distributed in correspondence with a desired exposure pattern; a driving and supporting means (406) for supporting and carrying the substrate to move with at least three degrees of freedom; and a measuring element (500) for measuring an angle between coordinate systems of the interference unit (300) and the means (406) to adjust an exposure position of the means (406) based on a measurement result of the measuring element (500) before exposing the substrate.