Probe Device With Adjustable Camera Axis for Variable-Thickness Samples
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Solution Overview
Problem
Existing defect inspection devices face challenges in accurately and safely approaching probes to semiconductor samples due to variations in sample thickness, leading to potential probe damage and reduced inspection throughput.
Innovation Solution
A probe device with a sample stage, probe unit, and first camera system that allows for optical axis adjustment perpendicular to the sample surface, enabling precise alignment and safe, rapid approach of the probe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the probe is approached rapidly to the sample using a fixed optical axis camera, then inspection throughput is improved, but measurement precision of the separation distance deteriorates due to sample thickness variations
Solution Approach 1:
The optical axis of the first camera is made adjustable in the vertical direction rather than fixed. This allows the camera to dynamically adapt its optical axis position to match different sample thicknesses, enabling accurate separation distance measurement while maintaining rapid probe approach capability. The adjustment mechanism lets the camera optimize its viewing angle for each sample, resolving the contradiction between speed and precision.
Solution Approach 2:
The system changes the optical parameter (optical axis position) of the first camera to adapt to different measurement conditions. By adjusting the optical axis vertically, the camera can accommodate samples of varying thicknesses, ensuring that the separation distance between probe and sample surface is accurately measurable regardless of sample dimensions, thus improving both throughput and precision.
2Measurement precision
If the probe is approached closer to the sample limit, then measurement precision is improved, but the probe may be damaged due to impact
Solution Approach 1:
The first camera provides real-time visual feedback on the separation distance between the probe and sample surface. By continuously monitoring this distance and comparing it to a predetermined safe threshold, the system can detect when the probe is approaching too closely and automatically adjust the approach speed or stop the approach, preventing impact damage while allowing precise measurement when conditions are safe.
Solution Approach 2:
The system establishes a predetermined safe separation distance threshold before the probe contact occurs. This threshold acts as a protective buffer, allowing the probe to approach close to the sample for precise measurement while ensuring it never gets close enough to cause impact damage. The threshold provides advance protection against probe damage.
3Device complexity
If the optical axis height is fixed, then device complexity is reduced, but adaptability to different sample thicknesses deteriorates
Solution Approach 1:
The first camera is equipped with a vertical adjustment mechanism that allows the optical axis height to be dynamically changed according to sample thickness. This dynamic capability enables the camera system to adapt to various sample dimensions without requiring multiple fixed cameras, achieving versatility while maintaining relatively simple system architecture through a single adjustable unit.
Data Source
AI summary
A probe device includes a sample stage 125 that supports a sample, a probe unit 143 to which a probe 141 brought into contact with a predetermined sample surface of the sample is attached, a first camera 111A that images the sample and the probe, and a first camera optical axis adjustment stage 112A that adjusts an optical axis of the first camera, in which the optical axis of the first camera is parallel to the sample surface, and the first camera optical axis adjustment stage allows the optical axis of the first camera to be moved in a direction perpendicular to the sample surface.