Wafer Carrier Pre-Staging for Congestion-Aware Fab Transport
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer delivery systems in semiconductor fabrication facilities face challenges with increased demand due to larger wafer sizes, leading to traffic jams and inefficiencies in cross-floor and cross-phase transportation, which affect production rates and wafer yield.
Innovation Solution
A transport system and method that involves a semiconductor apparatus, a stocker, an Over Hoist Transport (OHT) system, and a control system to pre-transport wafer carriers before load ports are available, optimizing the timing and path of wafer carrier movement to reduce waiting periods and increase production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automated material handling systems are used to increase transportation volume, then productivity is improved, but traffic jams occur leading to loss of time
Solution Approach 1:
The system performs preliminary actions by transporting wafer carriers to standby positions before the semiconductor apparatus is ready to receive them. The control system monitors apparatus status and initiates transport operations in advance, so that carriers are positioned and ready when the apparatus becomes available, eliminating waiting time and preventing traffic congestion.
2Productivity
If cross-floor and cross-phase transportation is increased to handle larger wafer sizes, then productivity is improved, but traffic jams occur leading to loss of time
Solution Approach 1:
The system transports wafer carriers to intermediate standby positions in advance of when they are needed by the semiconductor apparatus. This preliminary positioning allows the transport system to prepare for cross-floor and cross-phase transportation without creating congestion, as carriers are staged ready for immediate transfer when apparatus become available.
3Device complexity
If wafer carriers are transported only when load ports are available, then device complexity is reduced, but loss of time increases due to waiting periods
Solution Approach 1:
The control system performs preliminary actions by monitoring semiconductor apparatus status and initiating wafer carrier transport before load ports are actually available. Carriers are moved to standby positions in advance, so when the apparatus becomes ready, the carriers are already positioned and can be loaded immediately, eliminating waiting periods while maintaining manageable system complexity through automated monitoring.
Data Source
AI summary
A transport system is provided. The transport system includes a stocker configured to store an assigned wafer carrier and having a gate port. The transport system also includes a semiconductor apparatus configured to transmit a request signal including a processed time according to a processing wafer carrier loaded on the semiconductor apparatus. The transport system further includes a vehicle configured to transport the assigned wafer carrier from the gate port to the semiconductor apparatus and a control system configured to control the vehicle. When the control system receives the request signal, the control system controls the stocker to transport the assigned wafer carrier inside of the stocker to the gate port at a start time, which is earlier than the processed time, and the control system controls the vehicle to transport the assigned wafer carrier from the gate port to the semiconductor apparatus.