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

Paper DI-TuA7
Direct Observation of Atomic Disordering at the SrTiO@sub 3@/Si Interface Due to Oxygen Diffusion

Tuesday, October 30, 2001, 4:00 pm, Room 130

Session: High K Dielectrics III
Presenter: V. Shutthanandan, Pacific Northwest National Laboratory
Authors: V. Shutthanandan, Pacific Northwest National Laboratory
S. Thevuthasan, Pacific Northwest National Laboratory
Y. Liang, Pacific Northwest National Laboratory
Z. Yu, Motorola Labs
R. Droopad, Motorola Labs
Correspondent: Click to Email
Since CMOS devices based on the conventional dielectric material, SiO@sub 2@, will soon reach their dimensional limits in device technology, alternative high dielectric materials received much attention in recent years. Several oxides are being considered as alternative dielectric materials and strontium titanate is one of the most attractive choices of such materials. Recently, single crystal SrTiO@sub 3@(100) films have been successfully grown on Si(100) substrates at Motorola.@footnote 1@ The stability of these films that were grown at Motorola was studied as a function of temperature under various control environments including vacuum, hydrogen and oxygen using Rutherford backscattering spectrometry (RBS) along with channeling techniques, nuclear reaction analysis (NRA) and x-ray photoelectron spectroscopy (XPS) at Pacific Northwest National Laboratory (PNNL).@footnote 2@ Results from channeling measurements are consistent with the reported thin silicate/silica layer at the interface of an as grown sample. Annealing experiments in the vacuum and hydrogen indicate more disordering at the interface and in the bulk of the film due to oxygen movement from the film to the interface for the growth of silica. On the other hand, annealing in oxygen show improvements in crystalline quality of both film and interface. Experiments with isotopic labeled oxygen (@super 18@O) were carried out to understand the oxygen diffusion through the film to the interface using @super 16@O and @super 18@O nuclear reactions. Film collapses in the temperature range of 1070-1120 K regardless of the heating environment. @FootnoteText@ @footnote 1@ Z. Yu, J. Ramdani, J.A. Curless, C.D. Overgaard, J.M. Finder, R. Droopad, K.W. Eisenbeiser, J.A. Hallmakrk, and W.J. Ooms, J. Vac. Sci. Technol. B 18, 2139 (2000). @footnote 2@ Work conducted at PNNL was supported by the DOE Laboratory Technology Research (LTR) Program and by Office of Biological and Environmental Research (OBER).