OHT Taxi mode Meanwhile, to utilize the tool library, different reticles needed to be transferred to the tools in sequence. For a two-reticle scenario, when the first reticle is on stage for inspection, the empty pod should be removed from the load port since the second pod with the second reticle will be transferred to the tool in advance. However, this scenario introduced an unforeseen RFID writing issue. Because both pod information and reticle information are linked together on the RTD system for dispatch handling, all the information should be accurate and correct. Thus, the RFID, which contains reticle ID information on the pod, needs to be cleared before it leaves the tool. However, the reticle inspection tool did not support changing the RFID on the pod. Thus, a feature called RFID-write was developed for the EAP system to change the RFID on the pod. With this feature, the original pod would be released (clear the RFID info, like Pod A in Figure 7) when being taken away from tool, while the new pod would be combined with the reticle (write reticle ID into RFID, like the pod B in Figure 7) when the pod carries a new reticle. So, the pod essentially acts like a taxi to carry different reticles, transferring them between the stocker and inspection tools. With this taxi mode, pod utilization has been highly improved and the library usage scenario during FA has not encountered any more issues affecting the RTD system.