Nanoimprint Mold Production Using Two-Layer Hard Mask Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing nanoimprint molds using the sidewall process face challenges in controlling the size of fine uneven patterns, leading to tilting, breaking, or deformation of sidewall patterns due to surface tension in wet processes, which results in reduced production yield and inability to form small-size fine uneven patterns.
Innovation Solution
A method involving the formation of a first and second fine pattern on the same surface using a two-layer hard mask structure, where the first hard mask layer is etched using a sidewall pattern and a second resist pattern as masks, allowing for precise control of pattern sizes and minimizing the impact of wet processes on the sidewall patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single hard mask layer is used in the sidewall process, then the process is simpler, but the size controllability of fine uneven patterns is poor
Solution Approach 1:
The single hard mask layer is segmented into two distinct layers: a first hard mask layer (e.g., chromium) and a second hard mask layer (e.g., silicon oxide). This segmentation allows each layer to serve different functions - the first layer provides etching selectivity while the second layer defines the final pattern dimensions, thereby achieving precise size control without excessive process complexity
Solution Approach 2:
The solution transitions from a one-layer to a two-layer hard mask structure, adding a dimensional aspect to the mask system. This layered approach enables independent optimization of each layer's thickness and material properties, providing additional degrees of freedom for controlling the etching process and final pattern dimensions
2Ease of manufacture
If wet processes are used to remove uncured resist film, then the resist is effectively removed, but the sidewall pattern is tilted, broken, or deformed due to surface tension
Solution Approach 1:
A release hole formation step is performed preliminarily before the sidewall pattern formation. These release holes provide drainage pathways that prevent liquid accumulation during wet etching processes, eliminating the surface tension effects that cause sidewall tilting and breaking while still allowing effective resist removal
Solution Approach 2:
The release holes act as intermediary structures that mediate between the wet etching process and the sidewall pattern. They provide a controlled pathway for liquid removal that prevents harmful surface tension effects from directly acting on the sidewall pattern, thus protecting pattern integrity during resist removal
3Length of moving object
If the sidewall pattern size is reduced to form smaller fine uneven patterns, then the miniaturization requirement is met, but the pattern becomes more susceptible to deformation from surface tension
Solution Approach 1:
Release holes are formed in advance before creating the sidewall patterns. This preliminary action ensures that when small-scale sidewall patterns are formed, the harmful surface tension effects during wet processing are already mitigated by the pre-existing drainage pathways, allowing miniaturization without sacrificing pattern integrity
Solution Approach 2:
The introduction of release holes changes the physical parameters of the wet processing environment by providing controlled liquid flow pathways. This parameter change reduces the effective surface tension forces acting on the sidewall patterns, enabling the fabrication of smaller patterns that would otherwise be too vulnerable to deformation
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 enables the high-yield production of nanoimprint molds with fine uneven patterns of different sizes on the same surface, maintaining pattern integrity and increasing production efficiency by preventing tilting and peeling of sidewall patterns.
Implementation Method 1
a first hard mask pattern formation step for etching the first hard mask layer by using the sidewall pattern and the second hard mask pattern as masks, and forming a first hard mask pattern; and a fine pattern formation step for etching the base material by using the first hard mask pattern as a mask, and forming the first fine pattern and the second fine pattern
Data Source
AI summary
In the method, a sidewall pattern is formed in a side wall of a first resist pattern that is formed on a second hard mask layer of a base material in which first and second hard mask layers are laminated in the order of description, a second hard mask pattern is formed by etching the second hard mask layer by using the sidewall pattern as a mask, a first hard mask pattern is formed by etching the first hard mask layer by using, as a mask, the second hard mask pattern and a second resist pattern that is formed on the first hard mask layer of the base material, and the first and second fine patterns are formed by etching the base material by using the first hard mask pattern as a mask.