Paired-Fiber Optical Bundle for Precise Spectral Endpoint Detection
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Solution Overview
Problem
Conventional optical systems for endpoint control in manufacturing microelectronics are inadequate in meeting the increased demands for precision and accuracy in substrate processing, particularly due to variations in etching environments and photomask patterns, leading to substandard devices.
Innovation Solution
An endpoint detection system utilizing an optical bundle with paired emitting and receiving fibers and an achromatic lens to collect and transmit spectral components efficiently, enabling precise reflectance determination of substrate surfaces without signal loss, ensuring accurate endpoint detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional optical systems are used for endpoint control, then device manufacturing can proceed with basic monitoring, but measurement precision and manufacturing precision deteriorate due to variations in etching environments and photomask patterns
Solution Approach 1:
The optical system is segmented into multiple independent optical paths, each with its own emitting and receiving fibers. This segmentation allows each path to independently measure specific spectral components reflected from the substrate, enabling precise detection of endpoint conditions while compensating for environmental variations through multi-point measurement
Solution Approach 2:
Achromatic lenses are introduced as intermediary optical elements to focus and direct specific spectral components onto the substrate surface and collect reflected light. These intermediaries enable precise control over which wavelengths are measured, allowing the system to selectively monitor spectral signatures that indicate endpoint conditions while filtering out noise from environmental variations
2Measurement precision
If spectral data collection is enhanced with multiple optical paths, then measurement precision improves, but device complexity increases
Solution Approach 1:
The optical bundle integrates multiple functions into a single component: emitting fibers deliver incident light, receiving fibers collect reflected light, and achromatic lenses focus specific spectral components. This multi-functionality allows the system to perform comprehensive spectral analysis while maintaining a compact structure that does not proportionally increase device complexity
Solution Approach 2:
Multiple optical paths are merged into a single optical bundle that interfaces with the substrate through one measurement point. This merging consolidates the complexity of multiple independent systems into a unified structure, reducing the number of separate components and simplifying integration while maintaining the precision benefits of multi-path measurement
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 system provides enhanced spectral data collection, allowing for precise determination of substrate profiles, reducing signal loss, and ensuring accurate endpoint detection, thereby improving the quality of microelectronic devices.
Implementation Method 1
The achromatic lens is configured to responsive to receiving a first light beam of the incident light from the first emitting optical fiber, direct a first set of spectral components of the first light beam to a first portion of a substrate surface. The achromatic lens is further configured to direct a second set of spectral components of the first light beam to a second portion of the substrate surface.
Implementation Method 2
The first emitting optical fiber is disposed at a pairing angle relative to the first receiving optical fiber. The optical bundle further includes a second set of optical fibers including a second emitting optical fiber and a second receiving optical fiber. The second emitting optical fiber is disposed at the pairing angle relative to the second receiving optical fiber.
Data Source
AI summary
An endpoint detection system for enhanced spectral data collection is provided. An optical bundle is coupled to a light source. The optical bundle includes an emitting optical fiber and a receiving optical fiber disposed at a pairing angle relative to the emitting optical fiber. The optical bundle is coupled to a collimator assembly that receives a light beam of incident light from the emitting optical fiber and directs spectral components of the light beam to first and second portions of a substrate surface. The collimator collects reflected spectral components produced by the spectral components directed to the substrate surface. The collimator assembly transmits the reflected spectral components to the receiving fiber, which transmits the reflected spectral components to a light detection component. A processing device coupled to the light detection component determines a reflectance of the substrate surface based on the reflected spectral components.