UV Nanoimprint Lithography with Element-Wise Stamp and Gas Pressure
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Solution Overview
Problem
UV nanoimprint lithography processes face challenges with thermal deformation and high pressure requirements, which hinder multi-layer alignment and can damage nanostructures, and existing methods are inefficient for large-area wafer imprinting due to non-uniform flatness and residual layer thickness issues.
Innovation Solution
A UV nanoimprint lithography process using a large-area, element-wise patterned stamp with UV-transparent materials and pressurized gas to ensure complete filling of nanostructures, allowing for high-precision and high-quality nanostructure formation across large areas without the need for high pressure or temperature, and an apparatus with a substrate chuck and pressure supply unit to manage the imprinting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high pressure (about 30 atmospheric pressures) is applied to imprint high-viscosity resist, then the resist can be completely filled into nanostructures, but previously fabricated nanostructures may be broken or damaged
Solution Approach 1:
The patent changes the physical state of the resist from high-viscosity to low-viscosity by using UV-curable materials that remain liquid at room temperature, eliminating the need for high pressure while still achieving complete filling of nanostructures
Solution Approach 2:
The patent replaces the mechanical pressing system (high pressure) with a UV-curing system, where the low-viscosity resist is drawn into nanostructures through capillary action and then cured by UV light, eliminating mechanical damage to nanostructures
2Ease of manufacture
If high temperature is used in nanoimprint process, then the resist can be melted and imprinted, but thermal deformation occurs which hinders multi-layer alignment
Solution Approach 1:
The patent changes the processing conditions from high temperature to room temperature by using UV-curable materials, eliminating thermal deformation while maintaining ease of resist processing through UV illumination
Solution Approach 2:
The patent replaces thermal processing with UV-curing, where the resist is not melted but rather cured by UV light, eliminating thermal deformation and enabling precise multi-layer alignment
3Productivity
If a large-area stamp is used to imprint the entire wafer at once, then the imprinting time is reduced, but the flatness error becomes more serious causing non-uniform residual layer thickness
Solution Approach 1:
The patent segments the stamp into multiple element stamps arranged in a matrix pattern, where each element stamp covers a small region. This allows the entire wafer to be imprinted systematically through multiple steps while maintaining uniform flatness and residual layer thickness across the large area
4Adaptability or versatility
If the gap between stamp and wafer is not constant (e.g., Si wafer: 20-30 μm), then the stamp can accommodate wafer variations, but the resist may be insufficiently pressed during imprinting
Solution Approach 1:
The patent applies local quality by using element-wise patterned stamps where each element stamp is independently positioned and pressed against the wafer surface. This allows each local region to be imprinted with consistent pressure despite variations in the overall gap distribution, ensuring uniform resist filling across the entire wafer
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
Enables efficient and cost-effective formation of high-precision nanostructures on large-area substrates with reduced errors in flatness, allowing for faster and more uniform imprinting of nanostructures across the entire surface.
Implementation Method 1
Pressed resists may be cured by illuminating the resists with UV light to cure the resist
Data Source
AI summary
A UV nanoimprint lithography process and its apparatus that are able to repeatedly fabricates nanostructures on a substrate (wafer, UV-transparent plate) by using a stamp that is as large as or smaller than the substrate in size are provided. The apparatus includes a substrate chuck for mounting the substrate; a stamp made of UV-transparent materials and having more than two element stamps, wherein nanostructures are formed on the surface of each element stamp; a stamp chuck for mounting the stamp; a UV lamp unit for providing UV light to cure resist applied between the element stamps and the substrate; a moving unit for moving the substrate chuck or the stamp chuck to press the resist with the element stamps and substrate; and a pressure supply unit for applying pressurized gas to some selected regions of the substrate to help complete some incompletely filled element stamps.