AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS1+MS-WeA

Paper PS1+MS-WeA1
Supervision of Plasma Processes using Multiway Principal Component Analysis

Wednesday, October 4, 2000, 2:00 pm, Room 310

Session: Sensors and Control in Plasma Processing
Presenter: D. Knobloch, Infineon Technologies AG, Germany
Authors: D. Knobloch, Infineon Technologies AG, Germany
F.H. Bell, Infineon Technologies AG, Germany
K. Voigtlaender, Fraunhofer Institute IVI, Germany
J. Zimpel, Fraunhofer Institute IVI, Germany
Correspondent: Click to Email
In modern IC-manufacturing lines, plasma processing is still one of the most complex single process steps. The trend towards even smaller feature sizes and greater wafer diameters results in the need of better process and equipment control. In previous studies@footnote 1,2@, we have shown that an OES-system, based on a multiband CCD-spectrometer and operated with a home built software, can be used for run-to-run and real time process control. In this work, we show how we extended our software tool in order to improve data analysis. A MPCA (Multiway Principal Component Analysis) has been implemented that allows extraction of key numbers from spectral data simultaneously in time and wavelength. Key numbers are extracted for single processes as well as for run-to-run variations. As an example, the chamber conditions as a function of rf-hours and process mix is characterized by MPCA key numbers. It is shown, that the key numbers represent the cleanliness of the plasma chamber that depends on the process mix. Consequently, the key numbers can be used to establish an optimum product flow in the chamber in order to optimize wet clean cycles and control particle generation. Furthermore, we demonstrate, how fault detection, such as determination of gas flow variations or chamber leaks, can be achieved. The MPCA key numbers of misprocessed wafers show variations to processing of good wafers and can be correlated to certain equipment or process faults. However, the establishment of a catalogue with spectral pattern of fault classifications, such as chamber leaks, is needed. Consequently, preventive maintenance is triggered in order to fix the observed equipment faults as soon as possible. @FootnoteText@ @footnote 1@ D. Knobloch et al, November 1998, AVS 45th International Symposium, Baltimore @footnote 2@ D. Knobloch et al, October 1999, AVS 46th International Symposium, Seattle