Characterisation of HfO2 deposited by photo-induced chemical vapour deposition

Abstract The deposition of thin Hafnia (HfO2) films on crystalline Si by photo-induced chemical vapour deposition (CVD) using 222 nm excimer lamps at temperatures between 300 and 450 °C is presented. Hafnium (IV) tetra-t-butoxide was used as the precursor, which was carried into the photochemical reaction chamber by flowing Ar carrier gas at a pressure of several mbar using a special precursor injection system. Films from approximately 6–70 nm in thickness with refractive indices from 1.60 to 1.85 were grown. The deposition rate measured by ellipsometry was found to be 15 nm min−1 at a temperature of 400 °C. The deposited HfO2 films were characterised by various techniques. XRD showed that as-deposited HfO2 films were basically amorphous. Fourier transform infrared spectroscopy, revealed that Hf-O absorption in the photo-CVD deposited HfO2 films is quite different at various deposition parameters. The substrate temperature, system pressure and UV-annealing dependence of the physical and interfacial properties of these films will also be presented.

[1]  Ian W. Boyd,et al.  Photoinduced growth of dielectrics with excimer lamps , 2000, Advanced Laser Technologies.

[2]  S. Honda,et al.  Surface, structural and optical properties of sol-gel derived HfO2 films , 2000 .

[3]  Jeffrey T. Roberts,et al.  Chemical vapour deposition of the oxides of titanium, zirconium and hafnium for use as high-k materials in microelectronic devices. A carbon-free precursor for the synthesis of hafnium dioxide , 2000 .

[4]  J. Aarik,et al.  Influence of substrate temperature on atomic layer growth and properties of HfO2 thin films , 1999 .

[5]  A. Heuer,et al.  Electrical properties of TiO2 thin films formed on self-assembled organic monolayers on silicon , 1998 .

[6]  Ian W. Boyd,et al.  Thin tantalum pentoxide films deposited by photo-induced CVD , 1998 .

[7]  Jack C. Lee,et al.  Thermal stability and electrical characteristics of ultrathin hafnium oxide gate dielectric reoxidized with rapid thermal annealing , 2000 .

[8]  I. Boyd,et al.  Thin tantalum and tantalum oxide films grown by pulsed laser deposition , 2000 .

[9]  D. Muller,et al.  The electronic structure at the atomic scale of ultrathin gate oxides , 1999, Nature.

[10]  Ian W. Boyd,et al.  Nanocrystalline TiO2 films studied by optical, XRD and FTIR spectroscopy , 2002 .

[11]  V. Macagno,et al.  Characterization of hafnium oxide films modified by Pt doping , 1995 .

[12]  Ian W. Boyd,et al.  XPS investigation of UV-annealed ultrathin Ta2O2 films on silicon , 2001 .

[13]  Ian W. Boyd,et al.  Structural and electrical properties of tantalum oxide films grown by photo-assisted pulsed laser deposition , 2002 .

[14]  W. Sproul,et al.  Reactive d.c. magnetron sputtering of the oxides of Ti, Zr, and Hf , 1997 .

[15]  Jun-Ying Zhang,et al.  Preparation of Ce1−xGdxO2−0.5x thin films by UV assisted sol–gel method , 2002 .

[16]  M. Cho,et al.  Interfacial reactions in the thin film Y2O3 on chemically oxidized Si(100) substrate systems , 1999 .

[17]  J. Robertson.  Band offsets of high dielectric constant gate oxides on silicon , 2002 .

[18]  M. Schulz.  The end of the road for silicon? , 1999, Nature.

[19]  H. Fukuda,et al.  Structural and Electrical Properties of Crystalline TiO2 Thin Films Formed by Metalorganic Decomposition , 1999 .

[20]  Ian W. Boyd,et al.  New large area ultraviolet lamp sources and their applications , 1997 .

[21]  A. Ogura,et al.  Effects of deposition conditions on step-coverage quality in low-pressure chemical vapor deposition of HfO2 , 2002 .

[22]  J. Aarik,et al.  Texture development in nanocrystalline hafnium dioxide thin films grown by atomic layer deposition , 2000 .

[23]  Ian W. Boyd,et al.  CHARACTERISTICS OF HIGH QUALITY TANTALUM OXIDE FILMS DEPOSITED BY PHOTOINDUCED CHEMICAL VAPOR DEPOSITION , 1998 .

[24]  H. Iwai,et al.  1.5 nm direct-tunneling gate oxide Si MOSFET's , 1996 .

[25]  Ian W. Boyd,et al.  Photo-induced growth of dielectrics with excimer lamps , 2001 .

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

[27]  J.M.C. Stork,et al.  The impact of high-/spl kappa/ gate dielectrics and metal gate electrodes on sub-100 nm MOSFETs , 1999 .