AVS 50th International Symposium
    Thin Films Monday Sessions
       Session TF-MoM

Paper TF-MoM6
Characteristics of Hafnium Aluminate Films for Gate Dielectric Applications Deposited by Atomic Layer Deposition Method

Monday, November 3, 2003, 10:00 am, Room 329

Session: Atomic Layer Deposition
Presenter: J. Lee, Hanyang University, Korea
Authors: J. Lee, Hanyang University, Korea
J. Koo, Hanyang University, Korea
Y. Kim, Pusan National University, Korea
H. Jeon, Hanyang University, Korea
Correspondent: Click to Email
The decrease of SiO@sub 2@ gate oxide thickness in sub-100nm metal-oxide-semiconductor (MOS) technology causes high leakage current and serious device reliability problems. To avoid these problems, high-k materials such as HfO@sub 2@ and Al@sub 2@O@sub 3@ have been mainly investigated as a potential candidate to substitute SiO@sub 2@ gate dielectric. However, these high-k materials have some supplement to be solved for applying to MOS device. Hafnium aluminate films would solve relatively high leakage current and low dielectric constant problems of HfO@sub 2@ and Al@sub 2@O@sub 3@, respectively. Hafnium aluminate films were expected to have amorphous structure of Al@sub 2@O@sub 3@ while maintaining high dielectric constant of HfO@sub 2@. Hafnium aluminate films were deposited on p-type Si substrates by atomic layer deposition (ALD) method using HfCl@sub 4@ and trimethylaluminium (TMA) as Hf and Al precursors, respectively, with H@sub 2@O as reaction gas. All samples were rapid thermal annealed at 800°C for 10 seconds in N@sub 2@ ambient. Forming gas anneal was performed in an H@sub 2@+N@sub 2@ atmosphere at 450°C for 30 minutes after Pt gate electrode deposition. The physical and chemical properties were analyzed by cross sectional transmission electron microscope (XTEM), Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS). The electrical and reliability characteristics including equivalent oxide thickness (EOT), hysteresis, leakage current and interface defects were analyzed by I-V and C-V measurements. In this study, the characteristics of hafnium aluminate films for gate dielectric applications deposited by atomic layer deposition method were investigated. The chemical compositions and heat-treatments effects on the electrical and reliability characteristics of hafnium aluminate films for gate dielectric applications will be mainly presented. @FootnoteText@ @footnote 1@M. Leskela, M. Ritala, Thin Solid Films, 409(2002), 138, 146.