IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Dielectrics Wednesday Sessions
       Session DI-WeM

Paper DI-WeM1
Growth of Tantalum Oxide Films by Chemical Vapor and Atomic Layer Deposition

Wednesday, October 31, 2001, 8:20 am, Room 130

Session: Atomic Layer Deposition for Silicon Devices
Presenter: S. Prasertchoung, University of Maryland
Authors: S. Prasertchoung, University of Maryland
S.-Y. Yang, University of Maryland
J.N. Kidder, University of Maryland
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The nucleation and growth of tantalum oxide thin films by chemical vapor and atomic layer deposition was studied. In the CVD process, the films were deposited using Ta(C@sub 2@H@sub 5@O)@sub 5@ and O@sub 2@ as precursors, where tantalum source was delivered to the process using direct liquid injection. Films with thickness of 1 to 50 nm were deposited on Si and Pt-coated Si substrates and characterized using ellipsometry, atomic force microscopy, X-ray diffraction, and electrical measurements. In the CVD process it was observed that the deposition rate was kinetically-limited at substrate temperatures up to 475 C with an activation energy of approximately 1 eV. At temperatures greater than 475 C the growth rate decreased significantly and film properties were poor with rough morphology. This behavior was characteristic of gas phase reaction effects, although similar behavior was observed even with sequential delivery of the oxygen and tantalum ethoxide, where reactions between the precursors were minimized. This effect may stem from reactions with by-products of the alkoxide decomposition, such as water and ethanol, which can have a large effect on the nucleation and growth. In this work we investigated the effect of water on the initial nucleation, the growth kinetics, and the film morphology for ultra thin films of tantalum oxide deposited in both chemical vapor deposition and atomic layer deposition processes where the precursors (Ta(C@sub 2@H@sub 5@O)@sub 5@, O@sub 2@, H@sub 2@O) were delivered under various sequences and conditions. @FootnoteText@ This work was supported by the NSF through the University of Maryland MRSEC(DMR 00-80008).