Wafer Bath Imaging for Uniformity and Bridging Detection
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Solution Overview
Problem
Achieving across wafer and wafer-to-wafer uniformity in bath chambers for large diameter wafers, such as 12-inch wafers, is a challenge in semiconductor manufacturing, particularly in processes like surface cleaning and thin film etching.
Innovation Solution
A method involving video monitoring of bath processes using cameras and light sources to capture and analyze light intensity, along with optional audio recording, to determine metrics and detect wafer bridging, enabling real-time process control and optimization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If video monitoring and light intensity analysis are implemented to detect wafer bridging and monitor bath processes, then measurement precision and process control are improved, but device complexity increases
Solution Approach 1:
The patent uses optical copying by capturing images and video of the bath process through a camera system. The light source illuminates the bath solution and wafers, creating optical copies (images) that are analyzed to detect wafer bridging and monitor process metrics without physically contacting or disturbing the process environment. This allows precise measurement while maintaining system simplicity.
Solution Approach 2:
The patent introduces an intermediary analysis system that processes optical data (images and video) to extract process information. The camera captures light intensity variations, and software algorithms analyze these variations to detect wafer bridging and determine bath process metrics. This intermediary layer enables accurate detection while keeping the physical bath system unchanged and relatively simple.
2Reliability
If real-time video capture and analysis are performed during wafer processing, then process monitoring capability is improved, but loss of time for data processing increases
Solution Approach 1:
The patent performs preliminary actions by continuously capturing video and analyzing light intensity data in real-time during the wafer processing operation. The system proactively monitors the bath process throughout the entire processing cycle, detecting wafer bridging and other anomalies as they occur rather than analyzing data after processing completes. This ensures reliable monitoring without significant time loss.
Solution Approach 2:
The patent maintains continuous useful action by performing uninterrupted video capture and real-time analysis throughout the wafer processing operation. The camera continuously records the bath process, and the analysis system continuously processes the video data to detect process anomalies. This continuous monitoring provides reliable process oversight without interrupting the manufacturing workflow or causing significant time delays.
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
Enhances process uniformity and detects defects like wafer bridging, leading to improved quality and efficiency in wafer processing.
Implementation Method 1
illuminating a side of the plurality of wafers with a light source; capturing a first image of a first portion of the side of the plurality of wafers
Implementation Method 2
capturing a video of the bath solution containing the first wafer during a first time interval; analyzing the video based on intensity of light captured in a frame of the video
Data Source
AI summary
An exemplary method of monitoring a bath process includes processing a first wafer by submerging the first wafer within a bath solution; capturing a video of the bath solution containing the first wafer during a first time interval; analyzing the video based on intensity of light captured in a frame of the video; and based on analyzing the video, determining a first metric of the bath solution during the first time interval.