Benefit Model of Virtual Metrology and Integrating AVM Into MES

Frequent monitoring in both tool and process is required to detect the quality issue early so as to improve the process stability of semiconductor manufacturing. However, more tool and process monitoring means more metrology operation cost and longer cycle time. Recently, a promising technology denoted virtual metrology (VM) has bloomed. VM can convert sampling inspection with metrology delay into real-time and on-line total inspection. Therefore, VM has now been designated by International SEMATECH Manufacturing Initiative and International Technology Road Map for Semiconductors as one of the focus areas for the next generation factory realization road map of the semiconductor industry. The authors have developed the so-called automatic virtual metrology (AVM) system to implement and deploy the VM operations automatically. The purpose of this paper is to develop a business model to measure the profitability of VM based on in-depth manufacturing practices and metrology operations required for semiconductor manufacturing. This paper also proposes a novel manufacturing system that integrates AVM into the manufacturing execution system (MES). The interfaces among AVM, other MES components, and run-to-run (R2R) modules in the novel manufacturing system are also defined such that the total quality inspection system can be achieved and the R2R capability can be migrated from lot-to-lot control to wafer-to-wafer control.