Interference Lithography System for Sub-100 nm Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithographic methods for fabricating periodic structures with periods less than 100 nm are costly and have limited depth of focus and spatial coherence requirements, making them inefficient for widespread use in micro- and nano-technology applications.
Innovation Solution
A system and method using space-invariant interference lithography with a photon source, a mask with a grating, and a sample holder, where the sample is positioned at a distance from the mask to achieve a stationary and distance-invariant intensity distribution, allowing for the use of non-coherent light sources and enabling the creation of periodic and quasi-periodic patterns with reduced spatial coherence requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithographic methods are used to fabricate periodic structures with periods less than 100 nm, then manufacturing precision is improved, but production cost increases significantly
Solution Approach 1:
The patent replaces conventional mechanical lithographic systems with an optical interference lithography system. By using interference patterns from multiple laser beams to directly write periodic structures, the method eliminates the need for expensive step-by-step lithographic processes, achieving both high precision and cost-effectiveness for sub-100 nm periodic structures
Solution Approach 2:
The patent employs periodic interference patterns created by multiple laser beams to directly form periodic structures. The interference of coherent light beams creates a stationary periodic intensity distribution that directly imprints the desired periodic pattern, enabling efficient fabrication of periodic structures with periods less than 100 nm
2Manufacturing precision
If traditional interference lithography is used, then periodic patterns can be generated, but the depth of focus is limited by spatial coherence requirements
Solution Approach 1:
The patent changes the coherence parameters of the light source by using multiple independent laser beams with relaxed coherence requirements. This allows the system to maintain interference patterns over larger depth ranges, extending the depth of focus while still achieving the desired pattern periodicity
Solution Approach 2:
The patent creates a stationary interference pattern that is invariant along the propagation direction by carefully balancing the optical paths and frequencies of multiple laser beams. This equipotential approach to phase relationships extends the depth of focus, allowing patterns to be formed over a larger axial range
3Manufacturing precision
If high-coherence light sources are used for interference lithography, then pattern quality is improved, but alignment precision requirements increase
Solution Approach 1:
The patent modifies the coherence parameters by using multiple laser beams with relaxed individual coherence requirements. The system achieves high pattern quality through the collective interference of these beams, which reduces the stringency of alignment precision requirements compared to traditional single-beam interference lithography
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 allows for cost-effective generation of periodic and quasi-periodic patterns with periods in the 10-100 nm range, increasing throughput and enabling pattern creation on substrates with topographical features, while reducing the need for precise alignment and high-coherence light sources.
Implementation Method 1
a mask having a grating for generating a periodic or quasi-periodic pattern
Implementation Method 2
interference lithography technique
Data Source
AI summary
A system for generating periodic or quasi-periodic patterns on a sample by means of an interference lithography technique includes a photon source, a mask and a sample holder. The mask has a grating for generating a predetermined pattern, wherein the mask is positioned at a first distance from the photon source. The sample holder is disposed at a second distance from the mask on a side facing away from the photon source. The second distance is selected to be where an intensity distribution is substantially stationary and distance-invariant, or the second distance is varied to obtain a desired average intensity distribution on the sample surface.