Probe Tip Proximity Detection for Constant-Force Surface Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods struggle to accurately and reliably determine when a probe tip is in proximity to or in contact with a sample surface, leading to potential damage from accidental punching-through and inconsistent contact force during electrical, mechanical, optical, and chemical measurements.
Innovation Solution
A method involving monolithically integrated probes with side electrodes and airgaps, using response signals such as capacitance, intensity, photocurrent, piezoresistance, and others to detect contact, with feedback controllers maintaining a constant contact force through incremental stage movements and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional probing methods are used to test semiconductor devices, then manufacturing speed can be maintained, but probe tips may accidentally punch through the sample surface causing damage
Solution Approach 1:
The system performs preliminary action by detecting probe tip proximity to the sample surface before actual contact is made. The proximity detection system identifies when the probe tip is approaching the sample surface, allowing the system to prepare for contact and adjust parameters to prevent punching-through damage while maintaining testing efficiency.
Solution Approach 2:
The system implements feedback by continuously monitoring the proximity between the probe tip and sample surface, then using this information to adjust the probing process in real-time. The feedback mechanism allows dynamic control of probe positioning and force application, preventing sample damage while maintaining high productivity.
2Measurement precision
If incremental movement with feedback control is implemented to maintain constant contact force, then measurement accuracy improves, but system complexity increases
Solution Approach 1:
The feedback controller continuously monitors the proximity detection signal and adjusts the probe positioning to maintain constant contact force. This feedback mechanism ensures measurement precision by compensating for variations in sample surface topology, probe positioning errors, and mechanical drift, while the automated control reduces the need for manual intervention.
Solution Approach 2:
The system replaces manual mechanical adjustment with automated feedback control. Instead of relying on operator skill to maintain constant contact force, the system uses electronic feedback loops and automated positioning mechanisms, reducing human error and improving measurement consistency while managing system complexity through automation.
3Measurement precision
If multiple response signals are monitored to determine contact, then contact detection accuracy improves, but measurement time increases
Solution Approach 1:
The system performs preliminary proximity detection before full contact is established. By detecting when the probe tip is approaching the sample surface using multiple response signals in advance, the system can prepare for contact and reduce the time needed for final contact determination, improving both accuracy and speed.
Solution Approach 2:
The system uses multiple response signals simultaneously to detect contact, applying partial monitoring of each individual signal while combining them for comprehensive detection. This approach provides robust contact determination through multiple indicators without requiring complete analysis of each signal, balancing accuracy with time efficiency.
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
Ensures safe and consistent contact with the sample surface, improving measurement repeatability and reliability by preventing damage and maintaining stable contact resistance during probing.
Implementation Method 1
measuring a capacitance between the probe and at least a monolithically integrated side electrode when the probe tip is not in contact with the sample surface
Implementation Method 2
The step movement of the stage is continuously adjusted by a feedback controller to maintain a constant contact force at each location on the sample surface
Data Source
AI summary
Micro and nanoscale probes are used in the semiconductor and thin film materials industries to test wafers and samples. Probes supply and measure signals to and from the sample. Signals could be electrical, mechanical, chemical, optical, or photonics. Techniques of capacitance response signal, intensity response signal, photocurrent response signal, piezoresistance response signal, a high frequency response signal, elongated image response signal, contrast response signal, electrical response signal, resonance response signal, current response signal, and/or current-in-plane response signal could be used to determine when the probe tips are in proximity or contact a sample surface.