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

Paper DI-MoA7
First Step Towards Crystalline Titanate-Si Integration: Formation of Atomic Layer Strontium Silicate on Si(001)

Monday, October 29, 2001, 4:00 pm, Room 130

Session: High K Dielectrics I
Presenter: S. Gan, Pacific Northwest National Laboratory
Authors: S. Gan, Pacific Northwest National Laboratory
Y. Liang, Pacific Northwest National Laboratory
S. Shutthanandan, Pacific Northwest National Laboratory
S. Thevuthasan, Pacific Northwest National Laboratory
Correspondent: Click to Email
Recent work showed that crystalline titanates grown on Si(001) exhibited promising properties as the potential high-K gate oxides for CMOS. One of the critical issues in this approach is the interfacial template layer that needs to possess favorable struc tural and chemical properties for growth of crystalline oxides on Si. We present our recent results on the study of the initial stage of oxide growth on Si(001). Using scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED), and Rutherford back scattering (RBS), we investigated the structural and chemical behaviors of six strontium based templates grown on Si. It was found that depending on the surface strontium coverage, the strontium-covered Si surfaces exhibit a series of reconstructions. These reconstructions not only had different atomic structures but also different stability against oxidation and the oxide growth. For instance, upon exposure to oxygen, the (3x2) reconstruction was converte d to a disordered (1x1) surface while the Sr/Si-(1x2) reconstruction remained intact. For the growth of oxides, the (1x2) structure was found to provide the most stable interface, as evidenced by a uniform layer in angular dependence XPS results, the lack of interfacial SiO@sub2@ layer, and the ability to form single-crystal SrO films on this structure. By combining results obtained from STM, XPS, RBS, and LEED, we correlated the interface structures with film properties, which allowed us to identify suitable interfacial templates for optimized growth of titanates. @FootnoteText@ Pacific Northwest Laboratory is a multiprogram national laboratory operated for the U.S. Department of energy by Battelle Memorial Institute under Contract DE-AC06-76RLO 1830.a.