Laser Interference Photolithography System for Large-Size Grating Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current laser interference photolithography systems face challenges in manufacturing large-size gratings with gradually changing periods, particularly in achieving high accuracy and short processing cycles, as they are limited to producing uniform or two-dimensional gratings and struggle with phase nonlinear errors and drift.
Innovation Solution
A laser interference photolithography system is developed, incorporating a control module with an angle measurement module and phase measurement interferometer, which adjusts beam angles and phases to ensure accurate exposure and phase locking, allowing for the production of large-area gratings with varying periods by using a combination of reflectors, lenses, beam splitters, and phase modulators to maintain precise fringe control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If traditional mechanical engraving or laser direct writing is used for large-area grating manufacturing, then the processing area can be large, but the manufacturing accuracy deteriorates and ghost lines appear
Solution Approach 1:
The patent replaces mechanical engraving and laser direct writing with laser interference photolithography. By using the interference of two laser beams to form periodic interference patterns on the photosensitive substrate, the system achieves high-precision grating manufacturing without mechanical contact or direct laser writing, thereby eliminating ghost lines and maintaining sub-wavelength accuracy across large areas.
Solution Approach 2:
The patent changes the fundamental parameter of the manufacturing approach from mechanical/laser direct methods to optical interference methods. By controlling the interference pattern parameters (wavelength, angle, polarization) of laser beams, the system achieves precise control over grating line formation, enabling high accuracy across large manufacturing areas without the limitations of traditional methods.
2Area of stationary object
If mechanical splicing is used to assemble large gratings, then the processing area can be large, but the splicing accuracy deteriorates and the process complexity increases
Solution Approach 1:
The patent replaces mechanical splicing with a continuous laser interference exposure process. By maintaining stable interference patterns across the entire substrate area and using a large-format photosensitive plate, the system manufactures complete large-area gratings in one continuous process, eliminating the need for mechanical assembly and associated splicing errors.
3Manufacturing precision
If conventional photolithography is used for high-accuracy grating manufacturing, then the manufacturing precision can be high, but the processing cycle lengthens
Solution Approach 1:
The patent uses periodic interference patterns generated by laser beams to expose the entire photosensitive substrate simultaneously. The periodic nature of the interference fringes allows complete grating patterns to be formed in a single exposure cycle, dramatically reducing processing time compared to sequential methods while maintaining high precision through the stability of laser interference.
Solution Approach 2:
The patent achieves continuous exposure of the entire substrate area through stable laser interference patterns. Unlike traditional methods that require sequential processing or mechanical movement, the interference pattern remains stationary and covers the full substrate, enabling continuous parallel exposure and significantly reducing the processing cycle while maintaining manufacturing precision.
4Area of stationary object
If laser interference photolithography is used for large-area grating manufacturing, then the processing area can be large, but phase drift and pattern stability deteriorate
Solution Approach 1:
The patent incorporates a feedback control system using a heterodyne interferometer to continuously monitor the phase of the interference pattern. The measured phase information is fed back to a phase modulator that adjusts the optical path length in real-time, compensating for environmental disturbances and maintaining pattern stability across large substrate areas throughout the exposure process.
Solution Approach 2:
The patent employs a heterodyne interferometer that serves multiple functions: it measures phase drift, provides feedback signals, and enables real-time pattern locking. This multi-functional device simultaneously performs measurement and control, ensuring interference pattern stability for large-area grating manufacturing without requiring separate stabilization systems.
5Stability of the object's composition
If heterodyne pattern locking is implemented for phase stability, then the pattern stability can be high, but the device complexity increases and it is limited to uniform gratings
Solution Approach 1:
The patent uses a heterodyne interferometer that performs multiple functions simultaneously: phase measurement, feedback generation, and pattern locking control. This multi-functional approach achieves high pattern stability without requiring separate measurement and control systems, thereby reducing overall device complexity while enabling both uniform and variable period grating manufacturing.
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 system enables the accurate manufacturing of large-size gratings with gradually changing periods by ensuring precise angle and phase adjustments, improving the accuracy and efficiency of the photolithography process, overcoming limitations of traditional methods.
Implementation Method 1
laser interference photolithography is an important technology for manufacturing the micro-nano array device by exposing the photosensitive substrate using the periodic pattern generated by the interference of two or more laser beams
Implementation Method 2
a grating beam-splitter, which splits a laser light into a plurality of beams
Implementation Method 3
this photolithography system exemplifies a pattern locking device based on the heterodyne measurement principle
Implementation Method 4
arranging three acousto-optic modulators in the interference light path
Data Source
AI summary
A laser interference photolithography system, comprising a laser device, a first reflector, a grating beam-splitter, a second reflector, a first universal reflector, a first lens, a second universal reflector, a second lens, a beam splitting prism, a control module, an angle measurement module, a third lens and a substrate. The control module comprises a signal processing terminal, a controller, and a driver. The signal processing terminal is connected to the angle measurement module, the controller is connected to both the signal processing terminal and the driver, and the driver is connected to both the first universal reflector and the second universal reflector. The laser emits a laser light that is split into two beams of light by the system, and the two beams of light are focused on the substrate for exposure.