AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Monday Sessions
       Session DI-MoM

Paper DI-MoM10
A Materials and Electronics Properties Study of the ZrO@sub 2@/Si and SiO@sub 2@ Interfaces

Monday, November 3, 2003, 11:20 am, Room 317

Session: Electronic Properties of High-k Dielectrics and their Interfaces
Presenter: C.M. Lopez, University of North Carolina, Chapel Hill
Authors: C.M. Lopez, University of North Carolina, Chapel Hill
N.A. Suvorova, University of North Carolina, Chapel Hill
A.A. Suvorova, University of Western Australia
M. Saunders, University of Western Australia
E.A. Irene, University of North Carolina, Chapel Hill
Correspondent: Click to Email
Zirconia, ZrO@sub 2@, thin films were grown on single crystal MgO(100), Si(100) and on amorphous SiO@sub 2@ by ion beam sputter deposition of Zr metal at room temperature and subsequent oxidation both in-situ and ex-situ at 250°C and 600°C, respectively. The optical properties of MgO, sputter-deposited Zr, and ZrO@sub 2@ were determined by in-situ spectroscopic ellipsometry in the photon energy range of 1.5-4.5 eV. Based upon ellipsometric thicknesses obtained, a volume expansion of 1.28 Zr to ZrO@sub 2@ was observed. This value is in contrast to the value assuming bulk densities, 1.54. Refractive index values for ZrO@sub 2@ ranged from 2.18 to 2.52 for the given spectral range. Time of flight mass spectrometry of recoiled ions (TOF-MSRI), analytical electron microscopy, and spectroscopic ellipsometry were used to investigate the material properties of all samples with special attention to the composition and extent of the interface formed between ZrO@sub 2@ and the Si substrate. To compliment these techniques, electrical measurements were performed on fabricated Pt/ZrO@sub 2@/Si capacitors also prepared in vacuo to determine the interface trap state density, fixed charge, and dielectric constant for the overall film stack. The nature of the interface is correlated with the resultant electronic properties of the interface.