Wafer Position Correction in Dual-Robot Transfer Systems
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Solution Overview
Problem
Current semiconductor wafer handling systems face challenges in increasing throughput due to wafer position errors during transfer, which affect processing efficiency and require manual corrections that can slow down the process.
Innovation Solution
The method involves measuring wafer position errors during transfer using a dual side-by-side end effector robot and using this data to adjust the trajectory of a second robot for precise wafer pick and placement, allowing for real-time corrections to center the wafers without the need for additional mechanisms at intermediate stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wafer position measurement and correction is implemented during transfer, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The system measures wafer position during transfer using sensors and feeds this information back to the control system. The control system then calculates correction values and adjusts the robot trajectory in real-time to compensate for position errors, achieving closed-loop control that improves manufacturing precision without requiring complex mechanical correction mechanisms at intermediate stations
Solution Approach 2:
Instead of using complex mechanical correction mechanisms at intermediate stations to physically adjust wafer position, the system replaces mechanical correction with computational trajectory adjustment. The control system modifies the robot's motion path based on measured position errors, substituting mechanical complexity with software-based correction
2Productivity
If real-time wafer position correction is performed, then productivity is improved, but measurement precision requirements increase
Solution Approach 1:
The system performs position measurement during the transfer process itself, before the wafer reaches its final destination. This preliminary measurement allows the control system to calculate and apply corrections during the remaining transfer distance, ensuring accurate positioning without requiring excessively precise measurement at the moment of placement
Solution Approach 2:
The system dynamically adjusts the robot trajectory based on real-time position measurements. The control system continuously monitors wafer position and modifies the motion path on-the-fly, allowing flexible adaptation to position errors while maintaining high throughput through continuous operation
Data Source
AI summary
Methods correcting wafer position error are provided. The methods involve measuring wafer position error on a robot during transfer to an intermediate station. This measurement data is then used by a second robot to perform wafer pick moves from the intermediate station with corrections to center the wafer. Wafer position correction may be performed at only one location during the transfer process. Also provided are systems and apparatuses for transferring wafers using an intermediate station.