Plasma Etching Wavelength Selection via Emission Intensity Comparison
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Solution Overview
Problem
Current semiconductor etching apparatuses using plasma face challenges in selecting relevant wavelengths from a large number of wavelengths for analysis, leading to increased analysis time due to the methods described in Japanese Patents No. 3179997 and No. 4086190, which either display all corresponding wavelengths or fail to provide a method for selecting wavelengths efficiently.
Innovation Solution
The solution calculates emission intensity near specified wavelengths using OES data and compares it with stored emission intensity information to identify and extract relevant wavelengths for analysis, reducing the time required for analysis by determining similarity and ranking emission intensities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If all wavelengths corresponding to specified elements are displayed and analyzed, then comprehensive element analysis is achieved, but analysis time increases significantly
Solution Approach 1:
The patent extracts only the necessary wavelengths for analysis by comparing measured emission intensities with reference data. Instead of displaying all wavelengths corresponding to specified elements, the system selectively extracts wavelengths where the emission intensity ratio exceeds a threshold, thereby reducing analysis time while maintaining analysis quality.
Solution Approach 2:
The patent performs preliminary comparison of emission intensities against reference data before full analysis. By pre-calculating intensity ratios and identifying candidate wavelengths in advance, the system prepares a filtered set of wavelengths for detailed analysis, reducing the overall analysis time while ensuring comprehensive element detection.
2Productivity
If wavelength selection methods are simplified, then analysis speed increases, but wavelength identification accuracy decreases
Solution Approach 1:
The patent uses feedback mechanisms by comparing measured emission intensities with reference emission intensity ratios. The system continuously refines wavelength identification by checking whether intensity ratios at candidate wavelengths match reference values, ensuring accurate wavelength identification while maintaining fast analysis speed through iterative validation.
Solution Approach 2:
The patent changes the parameter used for wavelength selection from simple intensity thresholding to intensity ratio comparison. By using the ratio of emission intensities at different wavelengths compared to reference ratios, the system achieves accurate wavelength identification even with simplified selection criteria, balancing speed and 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 approach allows for the efficient selection of wavelengths used in etching processing analysis, significantly reducing analysis time by identifying and prioritizing wavelengths associated with specific elements based on emission intensity similarity.
Implementation Method 1
an optical emission spectroscope (OES) mounted thereon to monitor light emitted by plasma
Data Source
AI summary
An etching apparatus calculates an emission intensity in the vicinity of each of a plurality of wavelengths, at which a specified element should emit light, from information indicating light emission measured by an optical emission spectroscope during etching processing and, if it is determined that the calculated emission intensity information and emission intensity information stored in a storage unit are similar, extracts a wavelength, corresponding to the calculated emission intensity, with the wavelength associated with the element.