Development of a service management scheme for semiconductor factory management systems

Equipment managers generally function to communicate between the manufacturing execution system and equipment. There are hundreds of equipment in a semiconductor factory. In order to increase equipment utilization and improve product quality yield, more reliable services provided by equipment managers are expected. Therefore, it is essential to develop a reliable Service Management Scheme (SMS) for semiconductor factory management systems. In this work, the SMS is developed by applying the Jini and design by Contract technologies. A Generic Evaluator is also developed in the SMS so as to possess error-detection and function-replacement capabilities. The Generic Evaluator can also maintain the Credit values of all the equipment managers. By comparing the Credit values, the factory manager can select better equipment managers to provide services. With the SMS, the process status and parameters of equipment managers in service are stored periodically. If an equipment manager malfunctions, the Generic Evaluator detects and confirms it and sends an event notice to the factory manager. Then, the factory manager finds a spare equipment manager and transfers the backup process status and parameters to the spare equipment manager. Finally, the space equipment manager can continue monitoring the manufacturing process started from the point where the malfunctioned one left off. Evaluation of reliability improvement and an illustrative example of the SMS are also presented in the paper. The evaluation and demonstration results reveal that the proposed SMS establishes an efficient, reliable, fault-tolerant, and cost-effective mechanism for semiconductor factory management systems.