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-MoA8
High-k Metal Oxide Dielectrics Deposited by CVD using Oxygen and Ozone

Monday, October 29, 2001, 4:20 pm, Room 130

Session: High K Dielectrics I
Presenter: M. Yoon, University of Washington
Authors: M. Yoon, University of Washington
V.K. Medvedev, University of Washington
K.D. Hauch, University of Washington
J.W. Rogers, Jr., Pacific Northwest National Laboratory
Y. Ono, Sharp Laboratories of America
S.T. Hsu, Sharp Laboratories of America
Correspondent: Click to Email
TiO@sub 2@ thin films have generated considerable interest in high-k gate oxide applications. Previously we have described a novel process for creating high purity, carbon-free TiO@sub 2@ films on Si utilizing a TiO@sub x@ buffer layer.@footnote 1@ Here, improvements in oxidizing this buffering Ti layer using ozone (O@sub 3@) are presented. Auger electron spectroscopy (AES) analysis show similar stoichiometry of Ti and O when using either oxygen or ozone at room temperature. Low energy electron diffraction (LEED) analysis was conducted on Si, Ti/Si, and O@sub 2@ oxidized Ti/Si. Preliminary results show: an initial Si substrate with a highly ordered 2x1 structure prior to the deposition of Ti, a crystalline Ti film deposited on the Si, and the amorphorization of the Ti after oxidation with O@sub 2@. It is our aim to produce an amorphous TiO@sub 2@ film on the TiO@sub x@ buffer layer and thus the amorphous structure of this buffer layer is desired. Oxygen deficiency in TiO@sub 2@ gate oxide films is a major cause of increased leakage current. O@sub 3@ is an attractive alternative to O@sub 2@ as an oxidizer since it produces atomic oxygen (O) upon decomposition which can react with single dangling bond sites on the film surface, and thus create a denser, oxygen rich film. The co-deposition of the titanium isopropoxide (TTIP) precursor with O@sub 3@ for creating a CVD-TiO@sub 2@ film on the buffer layer has been compared to the co-deposition of TTIP with O@sub 2@. AES and electron spectroscopy for chemical analysis (ESCA) measurements show few compositional differences between the two TiO@sub 2@ films, however, atomic force microscopy reveals distinctly different morphology. The application of TiO@sub 2@ and other similarly produced metal oxide films (e.g. HfO@sub 2@) as gate oxides in MOS devices is also being explored. @FootnoteText@ @footnote 1@A. Tuan, M. Yoon, V. Medvedev, Y. Ono, Y. Ma, and J. W. Rogers, Jr., Thin Solid Films, 377-378 (2000) 766-771.