Automatic Virtual Metrology (AVM)

Virtual metrology (VM) can convert sampling inspection with metrology delay into real-time and online total inspection. This chapter describes the needs for physical metrology operation in semiconductor manufacturing and the necessity of reducing physical metrology with VM for decreasing manufacturing cost. Besides the fundamental functions of VM on-line conjecturing and VM quality evaluation, the automatic virtual metrology (AVM) server also possesses the functions of automatic data quality evaluation and automatic model refreshing. The Manufacturing Execution System (MES) is a shop floor control system which includes manual and/or automatic labor, production reporting, on-line inquiries, and links to tasks that take place on the production floor. A novel manufacturing system with AVM capabilities shall at least consist of a MES with an embedded AVM module and Run-to-Run controllers. An AVM system should be able to provide all kinds of VM applications and to realize automatic and fab-wide VM deployment.