Nanoimprint Lithography Uniformity via Segmented Etching
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Solution Overview
Problem
The existing methods of forming optical devices using nanoimprint lithography and etch processes face challenges in achieving uniformity due to uneven residual layers formed by different duty cycle features, leading to over-etching and decreased resolution.
Innovation Solution
The method involves depositing and etching multiple resist layers on a substrate with a hardmask using single-height stamps, allowing for separate processing of resist portions with varying duty cycles to prevent over-etching and improve uniformity, while using a blocking layer to manage etching steps effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If features having different duty cycles are imprinted onto a single optical device substrate using nanoimprint lithography, then the pattern complexity and device functionality are improved, but the residual layer becomes uneven leading to decreased manufacturing precision
Solution Approach 1:
The patent divides the imprinting process into multiple sequential steps, with each step handling a specific duty cycle range. The stamp is used multiple times with different resist layers, where each imprinting step processes features within a specific duty cycle window. This segmentation prevents the residual layer from becoming uneven by ensuring that each imprinting operation works on a uniform baseline, thereby maintaining manufacturing precision while achieving complex multi-duty-cycle patterns.
2Ease of manufacture
If a single-height stamp is used for multiple imprinting steps, then device complexity is reduced and ease of manufacture is improved, but processing time increases
Solution Approach 1:
The patent employs a single-height stamp that serves multiple functions across different imprinting steps. The same physical stamp, with its fixed feature heights, is reused to pattern different duty cycle ranges by varying only the resist layer thickness and etch parameters. This universal stamp approach simplifies manufacturing by eliminating the need for multiple specialized stamps, reducing stamp inventory complexity, and maintaining ease of manufacture despite the increased number of processing steps.
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 enhances the uniformity and resolution of optical device structures by preventing over-etching and maintaining processing efficiency through the use of a single-height stamp and separate etching of regions with different duty cycles.
Implementation Method 1
depositing a first resist layer on a substrate through a spin-on deposition process
Data Source
AI summary
Methods of forming optical devices using nanoimprint lithography and etch processes are provided. In one embodiment, a method is provided that includes depositing a first resist layer on a substrate, the substrate having a hardmask disposed thereon, imprinting a first resist portion of the first resist layer with a first single-height stamp, etching the first resist portion of the first resist layer, etching a first hardmask portion of the hardmask corresponding to the first resist portion of the first resist layer, removing the first resist layer and depositing a second resist layer, imprinting a second resist portion of the second resist layer with a second single-height stamp, etching the second resist portion of the second resist layer, and etching a second hardmask portion of the hardmask corresponding to the second resist portion of the second resist layer.