Back-Surface Camera Measurement Jig for Wafer Transfer Alignment
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Solution Overview
Problem
Existing substrate processing systems face challenges in transferring wafers strictly according to design values due to mechanical variations and installation-related issues, necessitating a precise measurement jig to account for actual mechanical variations.
Innovation Solution
A measurement jig equipped with front-surface and back-surface cameras, a level, vibration sensors, and a controller for data analysis and communication, which works in conjunction with an analysis controller and device controller to adjust and teach positions, ensuring accurate alignment and transfer operations within the substrate processing system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wafers are transferred using a transfer device according to design values, then the transfer process can be simplified and operated based on theoretical specifications, but mechanical variation and installation differences cause actual transfer positions to deviate from design positions
Solution Approach 1:
The measurement jig performs preliminary measurement of the actual transfer position before the actual wafer transfer operation. The camera captures the position of the measurement jig at the transfer destination, and the controller calculates the deviation from the design position. This preliminary action allows the system to compensate for mechanical variations by adjusting transfer parameters based on measured data, thereby resolving the contradiction between simplified operation and precise positioning.
2Measurement precision
If a measurement jig with multiple cameras and sensors is used to detect mechanical variations, then measurement precision and transfer accuracy are improved, but device complexity increases
Solution Approach 1:
The measurement jig integrates multiple functions into a single device: it serves as both a measurement tool with cameras for capturing position data and a reference object for determining transfer accuracy. The same measurement jig is used to measure positions at different locations (wafer supply location, transfer destination, etc.), eliminating the need for separate measurement devices at each location. This multi-functionality reduces overall system complexity while maintaining high measurement precision.
Solution Approach 2:
The measurement jig acts as an intermediary object that bridges the gap between the transfer device and the measurement system. Instead of directly measuring wafer positions or device parameters, the measurement jig provides a known reference object that can be easily captured by cameras. The controller uses the measurement jig's known dimensions and features to calculate actual transfer positions, simplifying the measurement process while maintaining accuracy.
3Adaptability or versatility
If the measurement jig uses a disk of approximately the same size as a wafer, then the measurement process can be integrated into the existing wafer transfer system, but the camera must be positioned on the back surface requiring additional structural considerations
Solution Approach 1:
Instead of mounting the camera on the front surface of the measurement jig (which would interfere with wafer handling operations), the design inverts the camera position to the back surface of the disk. This allows the camera to capture images of the measurement jig's front surface and surrounding area without obstructing the transfer process. The controller processes images from the back-surface camera to determine position information, resolving the spatial conflict between camera placement and system integration.
Data Source
AI summary
A measurement jig for measuring the conditions in a device and a processing method are provided. A measurement jig having a substrate, a back-surface camera provided on a back-surface side of the substrate, and a controller configured to control the back-surface camera.