Nanoscale Probe Contact Detection Using Dither Resonance Signals

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Solution Overview

Problem

Precise positioning of nanoscale probe tips onto integrated circuits is challenging due to the difficulty in distinguishing probe tips from the background and uncertainty in sample surface position, making existing open-loop and closed-loop positioning systems impractical for nanometer-scale contact detection.

Innovation Solution

A method involving dithering the probe with a periodic motion and directing a beam of charged particles to detect contact by generating detector data, using a lock-in amplifier to filter frequency components and determine the probe's resonance frequency, allowing contact detection without precise surface knowledge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If open-loop positioning systems are used for probe placement, then the system complexity is low, but the positioning precision deteriorates due to inability to distinguish probe tips from background at nanometer scale

Engineering Contradiction:

Improvepositioning system complexityVSAvoidprobe tip positioning precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The probe is subjected to periodic dither motion at a specific frequency, causing it to vibrate when not in contact with the surface. This vibration creates a detectable signal that disappears upon contact, enabling precise contact detection without complex positioning systems.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

A periodic dither signal is applied to the probe to induce oscillatory motion. The periodic nature of this motion allows for frequency-based detection methods, where the presence or absence of the periodic signal indicates contact status, improving precision without increasing system complexity.

Inventive Principle:

Principle #19Periodic action

2Difficulty of detecting and measuring

If imaging-based contact detection methods are deployed, then contact detection capability is improved, but the device complexity increases due to requirements for nanometer-scale positioning information

Engineering Contradiction:

Improvecontact detection capabilityVSAvoidpositioning system complexity

Core Design Contradiction:

Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The mechanical imaging-based detection system is replaced with an electrical detection system that measures the probe's vibrational response. This substitution eliminates the need for complex nanometer-scale positioning information while maintaining contact detection capability through electrical signal analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

An electrical circuit is introduced as an intermediary between the probe and the detection system. This circuit measures the probe's vibrational state indirectly through electrical signals, avoiding the need for direct optical imaging and complex positioning systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If probe positioning tolerance is increased, then the ease of operation is improved, but the measurement precision deteriorates due to uncertain sample surface position

Engineering Contradiction:

Improveprobe positioning easeVSAvoidcontact location precision

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The probe system performs self-detection of its own contact state through monitoring its vibrational response. The probe essentially detects its own contact condition by sensing changes in its dither motion, eliminating the need for external positioning information and enabling operation with larger positioning tolerances.

Inventive Principle:

Principle #25Self-service

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 precise localization and contact detection of nanoscale probe tips with integrated circuits, improving the accuracy and efficiency of integrated circuit testing by reducing errors and damage from improper contact.

Implementation Method 1

generating detector data describing the periodic motion of the probe based at least in part on an interaction between the beam of charged particles and the region of the probe

Methodology Applied

Scientific EffectCharged particle interaction:

Implementation Method 2

Generating the detector data can include generating filtered data using a lock-in amplifier tuned to the dither frequency

Methodology Applied

Scientific EffectFrequency filtering:

Implementation Method 3

The dither frequency can be about equal to a resonance frequency of the probe

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS12546819B2Techniques for detecting probe landing in integrated circuit testing systems

Publication Date: 2026.02.10 FEI CO

AI summary

Systems, methods, and techniques for detecting a contact between a probe tip and a sample surface. A method can include dithering a probe in a plane substantially parallel with a surface using a periodic motion having a dither frequency. The method can include directing a beam of charged particles toward a region of the probe. The method can include generating detector data describing the periodic motion of the probe based at least in part on an interaction between the beam of charged particles and the region of the probe. The method can include displacing the probe toward the surface. The method can also include detecting a contact between the probe and the surface using the detector data.