Scanning Probe Nanolithography Closed-Loop Feedback

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Solution Overview

Problem

Scanning probe nanolithography systems typically operate in an open-loop manner, requiring pre-setting of parameters and shielding of external and internal influences to achieve high-quality nanostructures, which can be inefficient and prone to errors due to thermal drift and other disturbances.

Innovation Solution

A closed-loop nanolithography system that continuously monitors and adjusts writing parameters during the process using the same probe for writing and imaging, allowing for real-time feedback and stabilization of the patterning process, enabling more precise and uniform nanostructure creation across the write field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If open-loop nanolithography is used with pre-set parameters, then the system is simpler to operate, but the manufacturing precision deteriorates due to thermal drift and external influences

Engineering Contradiction:
Improveease of operationVSAvoidmanufacturing precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a closed-loop feedback system where the written nanostructure is imaged in real-time during the writing process. The measured positions are compared with target positions, and feedback signals are generated to adjust scanner drive waveforms, compensating for thermal drift and positioning errors dynamically during nanolithography operations

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the same scanning probe to both write and image the nanostructure, eliminating the need for separate measurement equipment. The system self-calibrates by using its own writing output as the measurement target, creating a self-contained feedback loop that automatically compensates for disturbances

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If real-time feedback imaging is implemented during writing, then the manufacturing precision improves, but the device complexity increases

Engineering Contradiction:
Improvemanufacturing precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The scanning probe serves multiple functions: it writes nanostructures during forward scanning and images the same structures during backward scanning. This multi-functionality eliminates the need for separate writing and imaging equipment, reducing overall system complexity while enabling real-time feedback for high precision manufacturing

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If continuous monitoring during writing is performed, then the reliability of nanostructure quality improves, but the productivity decreases due to additional measurement time

Engineering Contradiction:
ImprovereliabilityVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system alternates between writing mode (forward scan) and imaging mode (backward scan) in periodic cycles. This allows continuous monitoring of nanostructure quality without stopping the writing process, maintaining high reliability while keeping productivity high through efficient time multiplexing of write and read operations

Inventive Principle:
Principle #19Periodic action

4Device complexity

If the same probe is used for both writing and imaging, then the device complexity is reduced, but the measurement precision may deteriorate due to probe degradation

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system dynamically switches the probe's function based on scanning direction: writing during forward scans and imaging during backward scans. This dynamic role switching allows the single probe to perform both functions effectively, reducing device complexity while maintaining measurement precision through appropriate parameter adjustment for each mode

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3047335B1Scanning probe nanolithography system and method
Publication Date: 2020.01.08 SWISSLITHO AG
  • EP3047335B1 patent drawingFigure 1
  • EP3047335B1 patent drawingFigure 2

AI summary

A scanning probe nanolithography system comprising a probe to create nanostructures line (60) by line through writing said nanostructures (74) pixel by pixel along lines (61) on a sample. A positioning system is adapted to provide a positioning of the probe at a sequence of predetermined positions to the sample and its surface towards the probe and a control unit (50) is provided to control the positioning system for positioning the probe for a pixel-wise writing of said lines (61) through a writing unit. It further comprises a sensor unit adapted to detect a predetermined property of the written nanostructure (74), the sensor unit being connected to the control unit to adapt the control signals to be provided to the writing unit for writing the following line (61; 62) based on the measured signals (65; 66) of the predetermined property.