Residual Layer Thickness Measurement and Correction in Nano-Imprint Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nano-fabrication techniques, specifically imprint lithography, lack quantitative feedback for evaluating and improving residual layer thickness uniformity during the imprinting process, relying on unaided eye assessment of fringe patterns, which hinders precise control over feature dimensions and etching uniformity.
Innovation Solution
Implementing a film thickness measurement tool with an optical detection system to measure and analyze the residual layer thickness, using processor-controlled algorithms to adjust the drop pattern of polymeric material, allowing for precise control of residual layer uniformity by varying drop positions, volumes, and patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If unaided eye assessment of fringe patterns is used to evaluate residual layer thickness, then the evaluation process is simple and quick, but measurement precision and quantitative feedback are insufficient
Solution Approach 1:
The patent implements a feedback mechanism where the optical detection system measures residual layer thickness and provides quantitative feedback to the controller. The controller then adjusts the drop pattern of polymeric material based on this feedback to improve uniformity. This closed-loop feedback system resolves the contradiction by enabling precise measurement and control while maintaining operational simplicity through automated control.
Solution Approach 2:
The patent replaces the mechanical/visual assessment method (unaided eye observation of fringe patterns) with an optical detection system that uses light interference patterns to measure thickness. This substitution of measurement methodology enables quantitative, precise measurement without requiring complex mechanical measurement apparatus, thus improving measurement precision while avoiding excessive device complexity.
2Manufacturing precision
If fixed drop pattern of polymeric material is used during imprinting, then the process is simple and fast, but residual layer thickness uniformity cannot be optimized
Solution Approach 1:
The patent transitions from a static, fixed drop pattern to a dynamic, adjustable drop pattern. The controller modifies the drop pattern (positions, volumes, or patterns) based on feedback from the optical detection system. This dynamic adjustment enables optimization of residual layer uniformity while maintaining process efficiency through automated control, resolving the contradiction between manufacturing precision and productivity.
Solution Approach 2:
The patent changes key parameters of the drop pattern (such as drop positions, volumes, or distribution patterns) based on measured residual layer thickness variations. By adjusting these parameters dynamically, the system optimizes residual layer uniformity without requiring complete re-engineering of the imprinting process, thus maintaining productivity while improving manufacturing precision.
3Manufacturing precision
If residual layer thickness variations exceed 30 nm, then the imprinting process is faster with less correction, but critical dimension control and etching uniformity deteriorate
Solution Approach 1:
The patent uses feedback from the optical detection system to measure residual layer thickness and provides quantitative data to the controller. The controller then adjusts the drop pattern to correct thickness variations, keeping them below the 30 nm threshold. This feedback-controlled approach achieves the required precision for critical dimension control and etching uniformity while managing process control complexity through automation.
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
Achieves improved residual layer thickness uniformity, enhancing control over critical dimensions of patterned layers and minimizing variations below 30 nm, thereby improving the quality of imprinted and etched features.
Implementation Method 1
there is no quantitative feedback to improve the residual layer uniformity once the liquid is positioned between the template and the substrate
Data Source
AI summary
In nano-imprint lithography it is important to detect thickness non-uniformity of a residual layer formed on a substrate. Such non-uniformity is compensated such that a uniform residual layer may be formed. Compensation is performed by calculating a corrected fluid drop pattern.