Lithographic Structure Alignment via In Situ Reference Detection
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Solution Overview
Problem
Existing lithographic processes face challenges in precisely positioning and adapting partial structures during the production of expanded structures, requiring complex and expensive high-precision equipment and stabilization of ambient conditions, with existing reference structures being invariant and interfering with the final structure.
Innovation Solution
A method where a reference structure element is generated and detected in situ within the write field using an imaging measuring device, allowing for precise alignment and correction of partial structures without the need for complex recalibration of lithographic devices, enabling flexible and adaptable structure creation without a large-area mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-precision interferometric measuring devices are used to monitor and control substrate positioning, then positioning precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates optical copies (images) of reference structures using the imaging measuring device. These images are processed to determine actual positions of partial structures, replacing the need for complex interferometric measuring devices with a simpler imaging-based approach that achieves comparable precision through image analysis
Solution Approach 2:
The patent replaces mechanical interferometric measuring systems with an optical imaging system. Instead of using complex mechanical displacement tables with interferometric monitoring, the system uses an imaging measuring device to capture images of reference structures and calculates positions through image processing, substituting mechanical measurement with optical measurement
2Manufacturing precision
If reference structures are produced in a separate preparatory step on specially prepared substrates, then alignment capability is improved, but processing time and complexity increase
Solution Approach 1:
The patent generates reference structure elements as preliminary features during the lithographic writing process itself, before the final structure is completed. This allows the reference structures to be created in advance within the same process flow, eliminating separate preparatory steps while maintaining alignment capability
Solution Approach 2:
The patent merges the creation of reference structures with the lithographic writing process. Instead of producing reference structures in a separate preparatory step on specially prepared substrates, the system generates reference structure elements simultaneously with the main structure writing using the same writing beam and process steps, combining two operations into one
3Manufacturing precision
If the write field is smaller than the total structure, then the exposure device can achieve higher resolution, but multiple positioning steps are required increasing process complexity
Solution Approach 1:
The patent segments the total structure into multiple partial structures that are written consecutively in the limited write field. By dividing the overall structure into manageable segments and writing them in sequence with precise positioning between steps, the system achieves high resolution while managing the complexity of multiple writing operations
Solution Approach 2:
The patent implements feedback by detecting reference structure elements in each write field position and using this information to determine and correct positioning deviations. The actual positions detected from reference structures feed back into the positioning control system, allowing real-time correction of alignment errors between partial structures
4Manufacturing precision
If reference structure elements are generated with the writing beam in each positioning step, then alignment accuracy is improved, but the writing process time increases
Solution Approach 1:
The patent applies partial action by generating only the necessary reference structure elements at specific locations within each write field, rather than writing the entire structure at maximum intensity. The writing beam is used selectively to create reference markers where needed, and the imaging measuring device captures only the essential alignment information, reducing overall process time while maintaining alignment 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 method enables reliable alignment of partial structures, reduces the need for high-precision equipment, and allows for the creation of complex structures with improved accuracy, achieving error tolerances of less than 100 nm, and facilitates the production of both two-dimensional and three-dimensional microstructures.
Implementation Method 1
a structure is written by means of at least one writing beam (e.g. laser beam or electron beam) of an exposure device into the lithographic material by local irradiation
Implementation Method 2
a reference structure element... is detected by means of an imaging measuring device
Data Source
AI summary
The invention relates to a method for producing a structure in a lithographic material, wherein the structure in the lithographic material is defined by means of a writing beam of an exposure device, in that a plurality of partial structures are written sequentially, wherein for writing the partial structures a write field of the exposure device is displaced and positioned sequentially and that a partial structure is written in the write field in each case, and wherein for positioning of the write field a reference structure is detected by means of an imaging measuring device. For calibration of the write field in the respectively positioned write field, before, during or after writing a partial structure, at least one reference structure element assigned to this partial structure is produced in the lithographic material with the writing beam, wherein the reference structure element after the displacement of the write field is detected by means of the imaging measuring device for writing a further partial structure.