A simulation model to characterize the photolithography process of a semiconductor wafer fabrication

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex products are requiring ever higher efficiency from manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterizing and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the most complex processes in semiconductor manufacturing. Using state-of-the-art computer simulation and a structured modeling methodology a generic model of photolithography flexible manufacturing cells has been developed and used to mimic the actual performance of the tools. Comparison of the output from the model with data from the plant shows the quality of the model. This paper discusses the technique used to develop the simulation model and includes a details on the structured modeling approach employed to develop reusable generic model for optimizing photolithography process parameters.