Wafer Edge Height Detection Using Oblique Multi-Slit Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current techniques for detecting the height of a wafer edge in semiconductor manufacturing are inaccurate and inefficient, particularly near the edge, where image acquisition is incomplete, and require time-consuming pattern matching and complementation, hindering high-speed throughput.
Innovation Solution
Projecting first and second patterns from an oblique direction across a wafer surface, utilizing at least one image from either pattern to calculate the wafer height, ensuring accurate and rapid detection by minimizing detection errors and eliminating the need for time-consuming slit identification and complementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single two-dimensional slit light is projected on the wafer from an oblique direction, then the height detection process is simplified, but the detection accuracy near the wafer edge deteriorates due to incomplete image acquisition
Solution Approach 1:
The single slit light is divided into multiple slit lights (first, second, third, fourth slit lights) projected at different positions and angles. This segmentation allows each slit to capture height information from different regions of the wafer, ensuring complete coverage even near edges without requiring complex detection procedures for any single slit.
Solution Approach 2:
The invention transitions from a single oblique projection to multi-dimensional projection by introducing multiple slit lights from different positions and angles. This adds spatial dimensions to the detection system, enabling comprehensive height measurement across the entire wafer surface including edge regions.
2Measurement precision
If pattern matching and slit complementation are performed to improve wafer edge height detection accuracy, then measurement precision improves, but productivity decreases due to time-consuming processing
Solution Approach 1:
Multiple slit lights are projected simultaneously onto the wafer before measurement, ensuring that all necessary height information is captured in advance. This preliminary multi-slit projection eliminates the need for subsequent pattern matching and slit complementation operations, maintaining high productivity while achieving accurate edge detection.
Solution Approach 2:
The invention uses multiple copies of slit patterns projected from different positions and angles. These redundant slit images provide complete height information without requiring complex processing or complementation, as the information is already captured in the multiple copies.
3Measurement precision
If multiple slit lights are projected from different positions and angles, then wafer edge height detection accuracy improves through complete image acquisition, but device complexity increases
Solution Approach 1:
The multiple slit lights are generated using a universal optical system that can project slit patterns in various positions and angles. This multi-functional optical design achieves comprehensive height measurement without requiring separate specialized systems for each measurement location, controlling overall device complexity.
4Productivity
If a single slit image is used for height detection, then the detection process is fast, but reliability deteriorates near the wafer edge due to incomplete data
Solution Approach 1:
The invention merges multiple slit images captured from different positions and angles into a unified height measurement. This combination of multiple data sources ensures reliable height detection near the wafer edge while maintaining fast processing through simultaneous projection and integrated analysis.
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
Enables high-accuracy, high-speed detection of wafer height near the edge, facilitating the production of dies from the wafer edge and improving semiconductor manufacturing throughput.
Implementation Method 1
a method for detecting a height of the substrate by irradiating the planar substrate with a light from an oblique direction to detect a position of its reflected light
Data Source
AI summary
In a semiconductor manufacturing process, it is necessary to cut a die close to the edge of a wafer in order to obtain as many dies as possible from one wafer. Accordingly, with respect to a charged particle beam device and an optical inspection device used in a semiconductor manufacturing process, there is a demand for detecting the height of the wafer close to the edge of the wafer with high accuracy, in order to measure or examine close to the edge of the wafer with high accuracy. Further, there is a demand for high speed height-detection in order to realize high throughput for the semiconductor manufacturing process. In the present invention, the foregoing can be achieved by the following configuration: sandwiching a target region on a wafer, a first pattern and a second pattern are projected onto one side and the other side respectively of the target region from an oblique direction with respect to the wafer top-surface, enabling an image of the first pattern and/or second pattern to be used.