Structural and electrical properties of HfLaOx films for an amorphous high-k gate insulator

Thin HfLaOx films on Si(100) have been investigated as an alternative gate insulator. The introduction of La2O3 into HfO2 causes an increase of crystallization temperature. Furthermore, unlike other Hf-based amorphous materials such as HfSiOx or HfAlOx, the permittivity of HfLaOx keeps a high value (>20). The capacitance-voltage curve of metal oxide semiconductor capacitor using the HfLaOx dielectric film has shown a negligible hysteresis and no frequency dispersion, indicating very small degradations of both interface and bulk properties. In addition, a very low fixed charge density in HfLaOx films is demonstrated from a very small film thickness dependence of the flatband voltage.

[1]  L. Brixner.  Structural and luminescent properties of the LaHfO-type rare earth hafnates , 1984 .

[2]  E. Ruckenstein,et al.  Recent developments in the kinetic theory of nucleation. , 2005, Advances in colloid and interface science.

[3]  C. Wiemer,et al.  La2Hf2O7 high-κ gate dielectric grown directly on Si(001) by molecular-beam epitaxy , 2004 .

[4]  Athanasios Dimoulas,et al.  Complex admittance analysis for La2Hf2O7/SiO2 high-κ dielectric stacks , 2004 .

[5]  E. Cartier,et al.  Formation of a stratified lanthanum silicate dielectric by reaction with Si(001) , 2001 .

[6]  J. Robertson.  Band structures and band offsets of high K dielectrics on Si , 2002 .

[7]  A. Navrotsky.  Thermochemical insights into refractory ceramic materials based on oxides with large tetravalent cations , 2005 .

[8]  R. Wallace,et al.  Hafnium and zirconium silicates for advanced gate dielectrics , 2000 .

[9]  D. Schlom,et al.  Thermodynamic stability of binary oxides in contact With silicon , 1996 .

[10]  Akira Toriumi,et al.  Permittivity increase of yttrium-doped HfO2 through structural phase transformation , 2004 .

[11]  Alexandra Navrotsky,et al.  Effect of La and Y on Crystallization Temperatures of Hafnia and Zirconia , 2004 .

[12]  A. Toriumi,et al.  Kinetic Model of Si Oxidation at HfO2/Si Interface with Post Deposition Annealing , 2005 .

[13]  W. D. Wang,et al.  Electrical characteristics and suppressed boron penetration behavior of thermally stable HfTaO gate dielectrics with polycrystalline-silicon gate , 2004 .

[14]  Characterization of field-effect transistors with La2Hf2O7 and HfO2 gate dielectric layers deposited by molecular-beam epitaxy , 2006 .

[15]  Thermal Stability and Electrical Properties of (La2O3)1-x(Al2O3)x Composite Films , 2005 .

[16]  J. Schulze,et al.  Examination and evaluation of La2O3 as gate dielectric for sub-100nm CMOS and DRAM technology , 2005, Microelectron. Reliab..