AVS 45th International Symposium
    Partial Pressure Measurements and Process Control Topical Conference Friday Sessions
       Session PC-FrM

Paper PC-FrM4
Sensor Integration on a W-CVD Cluster Tool for Real-Time Process Monitoring and Control

Friday, November 6, 1998, 9:20 am, Room 317

Session: Process Monitoring and Control
Presenter: J.N. Kidder, Jr., University of Maryland
Authors: J.N. Kidder, Jr., University of Maryland
Y. Xu, University of Maryland
N. Gupta, University of Maryland
T. Gougousi, University of Maryland
G.W. Rubloff, University of Maryland
Correspondent: Click to Email
Research in in-situ chemical process sensing and sensor integration is motivated by the potential value of real-time and in-line sensing for metrology, control, and optimization. In this work, the chemical composition of a W-CVD process flow downstream of the reactor was analyzed using a differentially-pumped closed ion source mass spectrometry system. LabView software and data acquisition hardware were employed to integrate equipment state signals (total pressure, valve status, temperature, etc.) with mass spectrometer measurements so that time-synchronized system behavior was obtained and the relation between the equipment and process variables was established. The sensor integration allowed us to monitor the reaction process via the chemical composition of the gas-phase reaction products while capturing the dynamics of the reactant delivery and pump behavior through the process cycle. Generation of product species from the W nucleation and growth stages as well as other time-dependent variations in the downstream process flow composition were detected with rapid response time (~2 s), which provided insight to the reaction dynamics at critical stages in the process. In addition, this sensor fusion facilitates identification of subtleties like flow rate fluctuation and run to run effects which are important for process design and fault management.