Semiconductor Inspection Noise Removal via Reference Signal
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Solution Overview
Problem
The existing inspection devices for semiconductor samples using the OBIRCH method face limitations in increasing electric power supply due to noise interference from external power sources, which degrades the inspection accuracy of defective portions.
Innovation Solution
An inspection device with a reference signal output section connected in parallel to the semiconductor sample and a noise removal section that generates a noise removal signal by subtracting noise from the external power supply's output, allowing for increased power supply while minimizing noise influence on measurement results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electric power supplied to the semiconductor sample is increased to improve inspection accuracy, then measurement precision improves, but noise from external power supply devices mixes into the current signal and degrades measurement precision
Solution Approach 1:
The patent segments the power supply function by using a dedicated external power supply device (2) separate from the inspection device (1), and further segments the signal path by introducing a reference signal output section (24) that separately monitors the power supply output. This segmentation allows the inspection device to measure and compensate for noise from the external power supply without compromising the current signal quality.
Solution Approach 2:
The patent introduces a reference signal output section (24) as an intermediary element that captures the output signal from the external power supply device (2). This reference signal serves as a mediator that allows the inspection device to identify and subtract noise components from the current signal, enabling accurate measurements even when using high-power external supply.
2Object-affected harmful factors
If internal power supply is used to avoid noise, then noise interference is reduced, but electric power available to the semiconductor sample is limited
Solution Approach 1:
The reference signal output section (24) acts as an intermediary that bridges the external power supply device (2) and the inspection device (1). It captures the power supply output characteristics and transmits this information as a reference signal, enabling the inspection device to compensate for external noise and thus allowing the use of high-power external supply without suffering from noise interference.
Solution Approach 2:
The patent implements a feedback mechanism where the reference signal from the external power supply output is continuously monitored and used to generate a noise removal signal. This feedback loop allows the inspection device to dynamically compensate for noise variations in the external power supply, maintaining measurement accuracy while utilizing high power levels.
3Power
If external power supply device is used to increase power, then electric power to semiconductor sample increases, but normal mode noise from the power supply mixes into the current signal
Solution Approach 1:
The reference signal output section (24) serves as an intermediary that captures the exact output characteristics of the external power supply device (2). By monitoring this reference signal, the inspection device can identify noise components introduced by the power supply and subtract them from the current signal, thereby maintaining measurement precision while utilizing high power levels.
Solution Approach 2:
The patent converts the harmful noise from the external power supply into a useful reference signal. By monitoring the power supply output through the reference signal output section (24), the inspection device transforms the noise source into a compensatory reference that enables accurate noise removal, thereby converting a detrimental factor into a beneficial tool for maintaining measurement accuracy.
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 configuration enhances the inspection accuracy of defective semiconductor sample portions by effectively increasing the electric power supply while reducing noise interference, thereby improving detection capabilities.
Implementation Method 1
A reference signal output section (24) connected to the external power supply device (2) in electrical parallel with the semiconductor sample (S)
Implementation Method 2
A noise removal section (25) configured to output, based on the reference signal, a noise removal signal obtained by removing a noise component of the output of the external power supply device (2) from a current signal
Implementation Method 3
The current signal is output from the semiconductor sample (S) in response to application of a voltage from the external power supply device (2)
Implementation Method 4
An electrical characteristic measurement section (27) configured to measure an electrical characteristic of the semiconductor sample (S) based on the noise removal signal
Implementation Method 5
The inspection device applies a voltage to the semiconductor sample, and measures the electrical characteristic of the semiconductor sample in response to laser beam irradiation and scanning based on the current signal output from the semiconductor sample
Data Source
AI summary
An inspection device includes a reference signal output section, a noise removal section, and an electrical characteristic measurement section. The reference signal output section is connected to an external power supply device in electrical parallel with a semiconductor sample, and outputs a reference signal according to the output of the external power supply device. The noise removal section outputs a noise removal signal obtained by removing a noise component of the output of the external power supply device from the current signal output from the semiconductor sample based on the reference signal. The electrical characteristic measurement section measures the electrical characteristic of the semiconductor sample based on the noise removal signal. The inspection device measures the electrical characteristic of the semiconductor sample to which a voltage is being applied by the external power supply device and which is being irradiated and scanned with light. The inspection device outputs a defective portion of the semiconductor sample based on the electrical characteristic.