Photodetector Current Measurement for High S/N Ratio Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing optical probing technologies for semiconductor devices face challenges in achieving a high Signal-to-Noise (S/N) ratio when acquiring images, particularly when branching detection signals by frequency band, leading to degraded image quality and sensitivity.
Innovation Solution
An image generation apparatus that applies a constant voltage to a photodetector to supply current based on light intensity, generating images independently of the detection signal, thereby improving the S/N ratio without signal branching, and includes a transformer to convert voltages and current detectors to measure and generate signals accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the detection signal is branched according to frequency band to acquire multiple images, then multiple types of images (pattern image and EOFM image) can be acquired, but the S/N ratio of the images is degraded
Solution Approach 1:
The patent segments the detection signal processing into two independent paths: one path processes the detection signal for EOFM images, while the other path uses a separate current measurement system (power supply unit + current detector) for pattern images. This segmentation allows each image type to be acquired independently without signal branching, maintaining high S/N ratio while enabling multiple image types.
Solution Approach 2:
The patent introduces a current detector as an intermediary component that measures the current supplied to the photodetector independently of the detection signal. This intermediary measurement path enables pattern image acquisition without branching the detection signal, thereby maintaining signal integrity and S/N ratio while providing versatility for multiple image types.
2Device complexity
If the detection signal is used for both pattern image and EOFM image acquisition, then signal processing is simplified, but the S/N ratio is insufficient
Solution Approach 1:
The system segments the signal acquisition into two independent channels: the detection signal channel for EOFM images and a separate current measurement channel for pattern images. This segmentation increases device complexity slightly but dramatically improves S/N ratio by eliminating signal branching and interference.
3Measurement precision
If constant voltage is applied to the photodetector to supply current based on light intensity, then images can be acquired independent of detection signal, but additional power supply components are required
Solution Approach 1:
A power supply unit serving as an intermediary component is introduced to provide constant voltage to the photodetector. This intermediary power supply system enables independent current measurement for pattern images, improving S/N ratio while the current detector integrates the measurement function into the existing power supply infrastructure.
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
This approach allows for improved S/N ratio in image generation, preventing signal degradation and maintaining sensitivity, especially when acquiring pattern and EOFM images, and simplifies the configuration by eliminating the need for signal branching.
Implementation Method 1
a photodetector that detects the light
Implementation Method 2
a transformer that transforms the second voltage supplied from the power supply to the first constant voltage
Data Source
AI summary
An image generation apparatus is an image generation apparatus that generates an image based on measurement light from the semiconductor device, and the image generation apparatus includes an optical sensor that detects the measurement light, an optical sensor power supply that applies a constant voltage to the optical sensor to supply a current to the optical sensor, a current detector that generates a pattern signal according to magnitude of the current supplied to the optical sensor by the optical sensor power supply, and a control device that generates a pattern image based on the pattern signal.