Grating Line Angle Measurement for Stitch Quality Assessment
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Solution Overview
Problem
Existing methods for measuring stitch quality of grating structures in waveguides are expensive and time-consuming, and there is a need for improved methods to quantify this quality effectively.
Innovation Solution
A method involving the measurement of discrete coordinates along a line feature to determine line angle and rotation, using a measurement tool to identify starting points and calculate theoretical line features, allowing for accurate comparison with design specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement methods are used to measure stitch quality of grating structures, then measurement accuracy is maintained, but measurement cost and time consumption increase significantly
Solution Approach 1:
The measurement process is segmented into discrete coordinate measurements along the line feature. Instead of measuring the entire line feature at once, the method divides it into multiple measurable points (first coordinate, second coordinate, etc.) that can be measured sequentially, reducing the overall measurement time while maintaining accuracy through systematic data collection
Solution Approach 2:
The patent replaces complex mechanical measurement systems with a coordinate-based measurement approach using a measurement tool that identifies line features and calculates coordinates mathematically. This substitution of mechanical measurement with computational coordinate analysis reduces measurement time while preserving precision
2Measurement precision
If conventional measurement methods are used to measure stitch quality of grating structures, then measurement accuracy is maintained, but measurement cost increases
Solution Approach 1:
The patent creates a theoretical line feature by calculating coordinates based on measured points, rather than requiring complex physical measurement apparatus. This computational copying of the line feature geometry enables accurate stitch quality assessment through mathematical analysis instead of expensive specialized equipment
Solution Approach 2:
The measurement approach changes from direct physical measurement parameters to coordinate-based parameters. By measuring discrete coordinates (x1, y1), (x2, y2), etc., and calculating line angles from these parameters, the method reduces equipment costs while maintaining measurement precision through mathematical relationships
3Measurement precision
If multiple coordinates are measured along line features to determine line angle, then measurement accuracy improves, but measurement complexity increases
Solution Approach 1:
The line feature is segmented into multiple measurable coordinate points along its length. By measuring coordinates at different positions (first coordinate, second coordinate, etc.) and calculating the line angle from these segmented measurements, the method improves accuracy through multiple data points while managing complexity through systematic processing
Solution Approach 2:
The patent introduces a theoretical line feature as an intermediary between raw coordinate measurements and final line angle determination. This intermediary construct simplifies the analysis by providing a reference framework against which measured coordinates can be compared, reducing the perceived complexity of the measurement process
Data Source
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AI summary
A method and apparatus for determining a line angle and a line angle rotation of a grating or line feature is disclosed. An aspect of the present disclosure involves, measuring coordinate points of a first line feature using a measurement tool, determining a first slope of the first line feature from the coordinate points, and determining a first line angle from the slope of the first line feature. This process can be repeated to find a second slope of a second line feature that is adjacent to the first line feature. The slope of the first and second line features can be compared to find a line angle rotation. The line angle rotation is compared to a design specification and a stitch quality is determined.