A Load Balancing Method for Dedicated Photolithography Machine Constraint

The dedicated photolithography machine constraint in semiconductor manufacturing is one of the new issues of photolithography machinery due to natural bias. In this paper, we propose the heuristic Load Balancing (LB) scheduling approach based on a Resource Schedule and Execution Matrix (RSEM) to tackle this constraint. The LB method is to schedule each wafer lot at the first photolithography stage to a suitable machine, according to the load balancing factors among machines. We describe the proposed LB scheduling method and present an example to demonstrate the proposed method and the result of the simulations to validate the approach.