Photomask With Variable Thickness Patterned Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photomasks struggle to accurately form patterns between adjacent features that are extremely close, often resulting in connection or increased spacing due to limitations in exposure resolution, especially when using traditional methods like reducing light wavelength or modifying optical systems.
Innovation Solution
A photomask design featuring a substrate with defined regions, including a patterned layer with varying thicknesses and recesses in the third region between adjacent openings, which modifies light transmittance and phase shifting to enhance exposure resolution by controlling light transmittance and focus length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photomask design with uniform patterned layer is used, then manufacturing process is simple, but exposure resolution is limited when adjacent openings are extremely close
Solution Approach 1:
The patterned layer is designed with different thicknesses in different regions: first and second regions have a first thickness, while the third region between adjacent openings has a second thickness different from the first. This local variation in thickness modifies light transmittance and phase shifting specifically in the critical region between adjacent openings, enabling better pattern formation without complicating the entire structure
Solution Approach 2:
The invention transitions from a two-dimensional uniform patterned layer to a three-dimensional structure with varying thickness. By introducing vertical dimension variation through different thicknesses and recesses, the photomask controls light propagation in the third dimension, thereby improving resolution in the horizontal plane without increasing lateral complexity
2Manufacturing precision
If recesses are added in the third region, then light transmittance and phase shifting are modified to improve resolution, but manufacturing complexity increases
Solution Approach 1:
The patterned layer is segmented into multiple regions (first, second, and third regions) with different thickness characteristics. The third region contains recesses that are further segmented to create specific optical effects. This segmentation allows independent optimization of each region's function while maintaining overall manufacturability through systematic fabrication processes
3Manufacturing precision
If uniform thickness patterned layer is used, then fabrication is easier, but patterns between adjacent openings cannot be formed when openings are extremely close
Solution Approach 1:
The thickness parameter of the patterned layer is changed from uniform to variable across different regions. The first thickness in first and second regions is different from the second thickness in the third region, creating controlled optical path differences that enable pattern formation between closely spaced openings without requiring complex multi-layer structures
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 design effectively prevents pattern connection or excessive spacing between adjacent features, improving the resolution of the photolithographic process by allowing for closer pattern formation without connection, thereby enhancing the precision of semiconductor manufacturing.
Implementation Method 1
modifying the light transmittance, the focus length or the phase shifting at regions between adjacent openings
Implementation Method 2
modifying the light transmittance, the focus length or the phase shifting at regions between adjacent openings
Implementation Method 3
modifying the light transmittance, the focus length or the phase shifting at regions between adjacent openings
Data Source
AI summary
The present invention provides a photomask, comprising: a substrate, a first region, a second region and a third region are defined thereon, wherein the third region is disposed between the first region and the second region, a patterned layer disposed on the substrate, wherein the patterned layer comprises a first patterned layer disposed in the first region, a second patterned layer disposed in the second region, and a third patterned layer disposed in the third region, and wherein a thickness of the first patterned layer is equal to a thickness of the second patterned layer, the thickness of the first patterned layer is different from a thickness of the third patterned layer, and at least one recess disposed in the third region.