On-line scheduling of cluster tools based on hybrid quantum evolutionary algorithm

For on-line scheduling problem of cluster tools in semiconductor manufactory, this paper proposes an on-line scheduling method based on hybrid quantum evolutionary algorithm. This method determines the optimal wafer sequence by quantum evolutionary, while the heuristic algorithm determines the robot sequence based on the given sequence by two-stage recursion procedure. One recursion procedure is to search the feasible solution space of a new insert wafer in a forward stepwise manner, which guarantees both logic correctness and temporal constraints. The other computes the optimal solution among the feasible solution space obtained in the previous phase in a maximum backtracking manner. The simulations show that the mentioned method is effective for solving the large-scale scheduling problems.