A comprehensive control strategy for maximizing process capability

摘要

Advanced process control (ARC) has become a central issue in wafer fabs when it comes to quickly introducing new technologies into production or fine-tuning tool performance for maximum yields. A comprehensive control strategy, based on real-time multi-input multioutput (MIMO) ARC, can improve utilization of metrology data through sharing between control modules, while optimizing overall process integration by matching needed levels of control to specific process steps. This article describes how process engineers can relax control specifications for one set of tools, such as photolithography, while maximizing APC with closed-loop feedforward and feedback systems for another, such as etch.