TDI Sensor Array False Image Removal for Ultrafine Lithography
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Solution Overview
Problem
Existing pattern inspection tools face challenges in accurately detecting ultra-small defects in ultra-large-scale integrated circuit devices and large-area LCD panels due to the creation of false images caused by cosmic radiation and internal electrical noises, which are not effectively addressed by prior solutions that increase apparatus complexity and fail to remove noise influences.
Innovation Solution
A workpiece inspection apparatus utilizing a light-receiving device with multiple time delay integration (TDI) sensors, which generates a measured image by averaging pixel values and excluding abnormal values greater than a fiducial value, thereby reducing the impact of false images and improving inspection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cosmic radiation detection and removal techniques are employed, then false image influence is reduced, but apparatus configuration and structural complexity increase
Solution Approach 1:
The patent merges multiple TDI sensors into a single light-receiving device, combining their output signals to generate the measured image. This integration approach reduces the need for separate cosmic radiation detection systems while maintaining the ability to identify and exclude false images through signal processing, thereby improving reliability without proportionally increasing device complexity
Solution Approach 2:
The patent introduces signal processing mechanisms as intermediaries between the TDI sensors and the final measured image. These intermediaries process the raw sensor data to identify and exclude abnormal pixel values caused by cosmic radiation, effectively reducing false image influence without requiring direct physical detection hardware for each radiation event
2Measurement precision
If multiple TDI sensors are interconnected to generate measured image, then false image exclusion capability is improved, but device complexity increases
Solution Approach 1:
The patent divides the light-receiving device into multiple TDI sensors, each independently capturing image data. This segmentation allows the system to compare and exclude abnormal pixel values from individual sensors, improving measurement precision through redundancy while managing complexity through modular sensor design
Solution Approach 2:
The patent changes the operational parameters of the TDI sensors by adjusting integration time and signal averaging factors. By optimizing these parameters, the system achieves better false image exclusion capability through statistical signal processing, reducing the need for complex hardware interconnections while maintaining high measurement precision
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
The solution enables accurate pattern inspection by effectively excluding temporarily generated false images, enhancing the detection of ultra-small defects in ULSI devices and large-area LCD panels, thereby improving production yields and inspection efficiency.
Implementation Method 1
a light-receiving device having an interconnection of two or more time delay integration (TDI) sensors each being arranged by two or more line sensors each being arranged by two or more pixels
Data Source
AI summary
A workpiece inspection apparatus includes a measured image generator unit configured to measure a pattern of a workpiece and generate a measured image; and a comparator unit configured to compare the measured image to a fiducial image, wherein said measured image generator unit includes a light-receiving device having an interconnection of two or more time delay integration (TDI) sensors each being arranged by two or more line sensors each being arranged by two or more pixels, for generating as the measured image an average value of pixel values excluding an abnormal pixel value from pixels of each TDI sensor with respect to a position of the pattern of the workpiece.