A Neural Network Approach for Batching Decisions in Wafer Fabrication

This paper considers a stochastic batching problem for a batch process in wafer fabrication, where various numbers of wafer lots are allowed to process together in each batch, and wafer lots arrive randomly but not in a specified pattern. The objective is to determine the optimal size (number of wafer lots) of each batch with respect to the measure of minimizing the mean queueing time of wafer lots. For the problem, a multi-layer perceptron neural network model is proposed to make real-time batching control, and its effectiveness is investigated in comparison with that of the well-known minimum batch size policy.