Multi-Step Supervisory Control of Flash Memory Device Production Via a Simple First-Principles Model

摘要

The goal of this paper is to extend a framework of process automation that has been successful in the chemical process industry to a semiconductor manufacturing process. A simple physics model of a flash memory cell is presented, and a multi-step supervisory control strategy is simulated on a flash memory cell manufacturing process based on this model. The multi-step supervisory control strategy performs multiple optimizations of target inputs for a lot in the course of its processing. The proposed strategy is shown to confer a significant improvement in the regulation of product quality over a one-step supervisory control strategy and an open loop implementation. This improvement is primarily due to the ability of the optimizer to compensate for the effect of error introduced by step controllers.