Scanning Probe Beam Tracking With Steering Mirror Error Correction

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Solution Overview

Problem

Scanning probe microscopes face challenges in accurately tracking the motion of the probe tip during scanning, leading to errors in height measurements and image distortion due to misalignment and misalignment-induced errors in the steering mirror.

Innovation Solution

A method and system that uses a steering mirror to synchronize the detection beam with the scanning motion, obtaining height error measurements to correct image measurements, and employing actuators to adjust the steering mirror for precise tracking, with real-time or post-processing correction options.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the steering mirror is moved to track the scanning motion, then the detection beam follows the probe, but misalignment errors cause height measurement inaccuracies

Engineering Contradiction:
Improveheight measurement accuracyVSAvoidtracking accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses a vision system to detect the actual position of the probe and feeds this information back to the control system. The control system then generates corrected tracking drive signals that compensate for misalignment errors in the steering mirror, ensuring accurate height measurements despite tracking imperfections.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces purely mechanical tracking with a hybrid system that uses optical detection (vision system) and computational correction. Instead of relying solely on mechanical precision of the steering mirror, the system uses image processing and control algorithms to detect and correct tracking errors, substituting mechanical reliability with sensor-based feedback.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If the beam steering mirror rotates to track probe movement, then the detection beam remains focused on the probe, but alignment errors cause image distortion

Engineering Contradiction:
Improveimage qualityVSAvoidsteering system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The vision system acts as an intermediary between the steering mirror and the final image output. It detects misalignment and distortion caused by the steering mirror's rotation, provides feedback about these errors, and enables computational correction, thus mediating between the mechanical steering action and the quality of the final image.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts tracking parameters based on detected misalignment. The control system modifies tracking drive signals in real-time based on vision system feedback, changing operational parameters to compensate for steering mirror errors and maintain image quality despite the complexity of the steering mechanism.

Inventive Principle:
Principle #35Parameter changes

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

Enhances the accuracy of surface imaging by correcting height errors, ensuring precise tracking and improved image quality in scanning probe microscopes.

Implementation Method 1

steering a detection beam onto the probe via the steering mirror, the detection beam reflecting from the probe in the form of a return beam

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP4049041B1Method of imaging a surface using a scanning probe microscope and corresponding system using the method
Publication Date: 2025.11.26 INFINITESIMA LTD
  • EP4049041B1 patent drawingFigure 1
  • EP4049041B1 patent drawingFigure 2~5
  • EP4049041B1 patent drawingFigure 6

AI summary

A method of imaging a surface using a scanning probe microscope, the scanning probe microscope comprising a probe having a cantilever extending from a base support (2) to a free end, and a probe tip carried by the free end of the cantilever, and a steering mirror (13), the method comprising: scanning the probe laterally across the surface so that the probe follows a scanning motion across the surface; steering a detection beam onto the probe via the steering mirror, the detection beam reflecting from the probe in the form of a return beam; moving the steering mirror so that the detection beam follows a tracking motion which is synchronous with the scanning motion and the detection beam remains steered onto the probe by the steering mirror; using the return beam to obtain image measurements, each image measurement being indicative of a measured height of a respective point on the surface; obtaining an associated height error measurement for each point on the surface by comparing a target value of the steering mirror position to the actual position of the steering mirror position, each height error measurement being indicative of a respective error in the measured height; and using the height error measurements to correct the image measurements so as to generate corrected image measurements.