Tip-to-Tip Patterning with EUV and Hard Mask Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithography processes require multiple steps and extra layers to form small-sized Tip-to-Tip patterns, which is inefficient and increases the complexity of pattern transfer from amorphous silicon to a hard mask layer.
Innovation Solution
A method utilizing extreme ultraviolet lithography (EUV) and etching to reduce the number of lithography cutting layers by forming a Tip-to-Tip pattern through sequential deposition and etching of specific layers, including hard mask layers, sacrificial layers, and spacer layers, allowing for interlaced patterns to be transferred directly to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple lithography steps and extra lithography cutting layers are used to form small-sized Tip-to-Tip patterns, then the pattern formation capability is improved, but the process complexity and number of steps increase
Solution Approach 1:
The patent changes the lithography wavelength parameter from conventional wavelengths to extreme ultraviolet (EUV) wavelength, enabling direct formation of small-sized Tip-to-Tip patterns with halved period without requiring multiple lithography steps or additional cutting layers, thus resolving the contradiction between pattern formation capability and process complexity
Solution Approach 2:
The patent segments the pattern formation process into distinct functional layers: a first hard mask layer for initial patterning, a second hard mask layer for final pattern transfer, and a sacrificial layer for spacer formation. This segmentation allows each layer to perform its specific function efficiently, achieving complex patterns through simplified sequential steps
2Measurement precision
If extra lithography cutting layers are added to form small periodical patterns, then the pattern resolution is improved, but the number of lithography layers increases
Solution Approach 1:
The patent employs EUV lithography with a wavelength of 13.5nm, which provides sufficiently high resolution to directly form small periodical Tip-to-Tip patterns without requiring additional lithography cutting layers, thereby achieving high pattern resolution while reducing the total number of lithography layers
Solution Approach 2:
The patent introduces a sacrificial layer as an intermediary between the first and second hard mask layers. This sacrificial layer enables the formation of spacers that define the final pattern dimensions, allowing high-resolution pattern transfer without requiring extra lithography cutting layers
3Manufacturing precision
If multiple lithography steps are performed to transfer patterns from amorphous silicon to hard mask layer, then the pattern transfer accuracy is improved, but the manufacturing time and efficiency decrease
Solution Approach 1:
The patent performs preliminary patterning of the first hard mask layer using EUV lithography before forming the remaining layers. This preliminary action establishes the basic pattern structure early in the process, enabling subsequent layers to be formed and transferred more efficiently, thus improving both pattern transfer accuracy and manufacturing efficiency
Solution Approach 2:
The patent implements a continuous pattern transfer process where the pattern is sequentially transferred from the first hard mask layer through the sacrificial layer and spacer formation to the second hard mask layer without interrupting the useful action. Each step builds upon the previous step, maintaining continuous progress toward the final pattern, thereby improving manufacturing efficiency while preserving pattern transfer 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 achieves a small-sized Tip-to-Tip pattern with a halved period without the need for additional lithography layers, enhancing resolution and simplifying the process by using EUV lithography twice, thereby reducing the complexity and number of steps required.
Implementation Method 1
performing EUV lithography on the first photoresist layer to form a first patterned photoresist layer
Implementation Method 2
sequentially etching the first dielectric layer and the sacrificial layer to the upper surface of the second hard mask layer
Implementation Method 3
forming a spacer layer on the sidewall of the patterned sacrificial layer
Data Source
AI summary
The present invention disclosures a Tip-to-Tip pattern preparation method, comprising: providing a substrate, and sequentially forming a layer to be etched, a first hard mask layer, a second hard mask layer, a sacrificial layer, a first dielectric layer and a first photoresist layer on the substrate, forming a first patterned photoresist layer which has a first Tip-to-Tip pattern by EUV lithography, and transferring the first Tip-to-Tip pattern to the second hard mask layer by etching; then forming a second patterned photoresist layer which has a second Tip-to-Tip pattern by the EUV lithography, and transferring the second Tip-to-Tip pattern to the second hard mask layer by etching; finally, transferring the first Tip-to-Tip pattern and the second Tip-to-Tip pattern to the layer to be etched. The above method needs only performing the EUV lithography twice to form the small-sized Tip-to-Tip pattern with a period halved, that is, the EUV lithography and etching are used for reducing lithography layers and realizing to form the small-sized Tip-to-Tip pattern with the period halved.