Integrated process control for cluster tools using an in-line analytical module

The paper describes a novel analytical module for in-line process control in cluster tools. Having standardized mechanical and control interfaces (SEMI MESC/CTMC), the module can be easily attached to a cluster tool and integrated into the cluster control system like a process module. Equipped with an X-ray photoelectron spectrometer, the analytical module was used for in-line control of cleaning process in a gate stack cluster. The measurement results were available immediately after wafer processing and the process parameters could be optimized just for the next wafer. This module offers major advantages especially for fast process ramp-up and for process development.