AVS 46th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoA

Paper TF-MoA1
Plasma Interaction Effects in Ion-Beam Assisted Pulsed Laser Deposition of Al-O-N Films

Monday, October 25, 1999, 2:00 pm, Room 615

Session: Fundamentals and Applications of Ionized PVD
Presenter: A.A. Voevodin, Air Force Research Laboratory
Authors: A.A. Voevodin, Air Force Research Laboratory
J.G. Jones, Air Force Research Laboratory
J.S. Zabinski, Air Force Research Laboratory
Correspondent: Click to Email
Interactions between plasmas produced by a nitrogen ion-beam source and pulsed laser ablation of Al@sub 2@O@sub 3@ were studied. Plasma fluxes from both sources intersected on the substrate surface in a typical arrangement for ion-beam assisted pulsed laser deposition (AIPLD). The study was focused on the detection of temporal and spatial plasma distributions, excitation states, and chemical reactions in the substrate vicinity, which were not present when operating each of the plasma sources separately. Plasma emission imaging and spectroscopy analyses using an ICCD camera and a spectrometer were used to investigate plasma development and chemistry in real time using the initial laser pulse for synchronization. In the study, the N@sub 2@ background pressure was varied in the range from 0.08 to 4 Pa and X-ray photoelectron spectroscopy was performed for Al-O-N films. Film elemental compositions were correlated with plasma chemistry. Two significant plasma interaction effects were discovered. One resulted in a considerable activation of N and O and formation of NO in a near substrate region, which then reacted with Al to from Al-O-N. A maximum plasma excitation was observed at reduced 0.1-0.2 Pa N@sub 2@ pressures and provided the highest amount of N in the films. Above 1 Pa of N@sub 2@, the Al-O-N films had lower nitrogen content, even though more nitrogen was available for the deposition. Another interaction effect was observed in the 2-4 Pa pressure region, when formation of short lived plasma channels connecting ion-beam and laser ablated plasmas were detected. These channels resulted in plasma bending and shifting from the substrate surface, affecting film composition and influencing ion beam current extracted from an ion beam-source. The study suggested that the interaction of ion-beam and laser ablation plumes in IAPLD might considerably affect plasma chemistry, excitation stages, and spatial distribution, providing new opportunities for the control of resulting film properties. @FootnoteText@ Key words: ion-beam assisted pulsed laser deposition, plasma chemistry, Al@sub 2@O@sub 3@ ablation, aluminiumoxynitride.