Mixed Ti–O–Si oxide films formation by oxidation of titanium–silicon interfaces

Abstract The reaction of oxygen with titanium deposited on Si (1 0 0) surfaces has been studied at room temperature and low oxygen pressures, using XPS and ARXPS. The experimental results for Ti growth on Si can be explained using a model involving a two stage mechanism. The first stage is characterized by the formation of a uniform TiSi x layer ∼4 ML thick and the second one by the formation of metallic titanium that grows following a Stranki–Krastanov mechanism, that is, the formation of a Ti monolayer followed by the growth of Ti islands (7 ML thick) over the TiSi x layer previously formed. The oxidation of Ti/Si interfaces strongly depends on the interface that is oxidized. For an interface corresponding to the first stage of deposition a Ti–O–Si mixed oxide layer is formed on the near surface. This layer is on top of a multilayer structure which is composed of TiO 2 (Ti 4+ ), titanium suboxides along with Ti Si (Ti Si  + Ti 1+  + Ti 2+  + Ti 3+ ), and substrate when going from the outer surface to the substrate whereas for an interface corresponding to the second stage no Ti–O–Si mixed oxide is detected and a Ti 0 rich layer is observed between the titanium suboxides and the Si substrate.

[1]  L. R. Wilson,et al.  Fingerprints of spatial charge transfer in Quantum Cascade Lasers , 2007, 0708.1274.

[2]  T. Barr.  Recent advances in x‐ray photoelectron spectroscopy studies of oxides , 1991 .

[3]  D. A. Shirley,et al.  High-Resolution X-Ray Photoemission Spectrum of the Valence Bands of Gold , 1972 .

[4]  M. R. Shanabarger.  Comparative study of the initial oxidation behavior of a series of titanium–aluminum alloys , 1998 .

[5]  C. Palacio,et al.  Control of the optical properties of silicon and chromium mixed oxides deposited by reactive magnetron sputtering , 2011 .

[6]  S. Valeri,et al.  Oxygen chemisorption and oxide formation on Ni silicide surfaces at room temperature , 1984 .

[7]  C. Palacio,et al.  Growth of Ti–O–Si mixed oxides by reactive ion-beam mixing of Ti/Si interfaces , 2014 .

[8]  S. Alvarado,et al.  Core-level lifetimes as determined by x-ray photoelectron spectroscopy measurements , 1980 .

[9]  C. Palacio,et al.  The room temperature growth of Ti on sputter-cleaned Si(100): Composition and nanostructure of the interface , 2005 .

[10]  W. Stickle,et al.  Handbook of X-Ray Photoelectron Spectroscopy , 1992 .

[11]  Carlos Palacio,et al.  A family of smoothing algorithms for electron and other spectroscopies based on the Chebyshev filter , 2006 .

[12]  Zhufang Liu,et al.  Titania−Silica: A Model Binary Oxide Catalyst System , 1997 .

[13]  E. Pabón,et al.  TiO2-SiO2 mixed oxides prepared by a combined sol-gel and polymer inclusion method , 2004 .

[14]  Simulations of diamond nucleation in carbon fullerene cores , 2001 .

[15]  B. Han,et al.  Ti-Si mixed oxides prepared by polymer in situ sol-gel chemistry with the aid of CO2. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[16]  Microscopic and macroscopic dielectric description of mixed oxide thin films , 2007 .

[17]  C. Palacio,et al.  Ultrathin AlOx-TiOy film formation by controlled oxidation of titanium deposited on polycrystalline aluminum surfaces , 2002 .

[18]  C. Palacio,et al.  An XPS and ellipsometry study of Cr–O–Al mixed oxides grown by reactive magnetron sputtering , 2011 .

[19]  Shyam P. Murarka,et al.  Silicide thin films and their applications in microelectronics , 1995 .

[20]  K. Xie,et al.  Silica–Titania mixed Oxides: Si–O–Ti Connectivity, Coordination of Titanium, and Surface Acidic Properties , 2008 .