A
server, a
system and a method for automatic
virtual metrology (AVM) are disclosed. The AVM
system comprises a model-creation
server and a plurality of AVM servers. The model-creation
server is used to construct the first set of
virtual metrology (VM) models (of a certain equipment type) including a VM conjecture model, a RI (Reliance Index) model, a GSI (Global Similarity Index) model, a DQIx (Process
Data Quality Index) model, and a DQIy (
Metrology Data Quality Index) model. In the AVM method, the model-creation server also can
fan out or port the first set of VM models generated to other AVM servers of the same process apparatus (equipment) type, and each individual fan-out-
acceptor's AVM server can perform automatic model refreshing processes so as to
gain and maintain its VM models' accuracy.