AVS 50th International Symposium
    Vacuum Technology Thursday Sessions
       Session VT+MS-ThM

Paper VT+MS-ThM3
Towards Improved Control of PVD Processes for Nano-Structured Me-aC:H Coatings@footnote 1@

Thursday, November 6, 2003, 9:00 am, Room 323

Session: Reproducibility, Precision, and Accuracy of Vacuum and Process Measurements
Presenter: M.A. Taher, Caterpillar Inc.
Authors: M.A. Taher, Caterpillar Inc.
B. Feng, Caterpillar Inc.
A.G. Shull, Caterpillar Inc.
B. Johs, J.A. Woollam Company Inc.
G. Pribil, J.A. Woollam Company Inc.
C.C. Klepper, HY-Tech Research Corporation
E.P. Carlson, HY-Tech Research Corporation
R.C. Hazelton, HY-Tech Research Corporation
E.J. Yadlowsky, HY-Tech Research Corporation
Correspondent: Click to Email
The reliability and durability of machine components such as bearings and gears can be enhanced through the application of metal-containing amorphous carbon (Me-aC:H) coatings, deposited by physical vapor (PVD) techniques such as sputtering. Commercial sputtering systems used for tribological coatings often employ computerized recipe managers to attain a certain level of reproducibility in the coating process. In most cases, these recipe managers control the deposition process through an open loop, time stepping approach where deposition parameters are varied within a particular time frame, and the process is repeated consistently from batch to batch. This type of control generally provides a level of reproducibility that is acceptable in applications where the component benefits from the coating but does not depend on it for full functionality. However, in applications where the coating is integrated into the machine component design, creating a prime-reliance on the coating, higher levels of coating consistency are required. Such levels may involve the adoption of in-situ sensors integrated with a closed-loop deposition control system. To build such a successful control system, knowledge of the relationships between the input process factors, the sensed variables, and the critical coating characteristics is necessary. In this study, a set of in-situ sensors that included a residual gas analyzer, an optical emission spectrometer, an optical absorption spectrometer, a Langmuir probe and a spectroscopic ellipsometer were explored. Three Design-of-Experiment (DoE) test runs were conducted which explored the effects of the coating process input factors on the output sensor signals and the critical coating characteristics. Results of these experiments are presented and a closed-loop control strategy is discussed. @FootnoteText@ @footnote 1@This work was partially supported by the Department of Commerce through its NIST ATP program award number 70NANBH0H3048.