The structural and electrical properties of thermally grown TiO₂thin films

Abstract

We studied the structural and electrical properties of TiO 2 thin films grown by thermal oxidation of e-beam evaporated Ti layers on Si substrates. Time of flight secondary ion mass spectroscopy (TOF-SIMS) was used to analyse the interfacial and chemical composition of the TiO 2 thin films. Metal oxide semiconductor (MOS) capacitors with Pt or Al as the top electrode were fabricated to analyse electrical properties of the TiO 2 thin films. We show that the reactivity of the Al top contact affects electrical properties of the oxide layers. The current transport mechanism in the TiO 2 thin films is shown to be Poole-Frenkel (P-F) emission at room temperature. At 84 K, FowlerNordheim (F-N) tunnelling and trap-assisted tunnelling are observed. By comparing the electrical characteristics of thermally grown TiO 2 thin films with the properties of those grown by other techniques reported in the literature, we suggest that, irrespective of the deposition technique, annealing of as-deposited TiO 2 in O 2 is a similar process to thermal oxidation of Ti thin films.

Analysis of TiO2 for microelectronic applications: effect of deposition methods on their electrical properties

“…The electrical properties of TiO 2 films as the gate bias were also investigated. It can be noted that the as deposited film showed a relatively low leakage current (J L ) of about 10 -6 A/cm 2 at zero bias and 5.32Â10 -5 A/cm 2 at a gate bias of + 1 V. For higher gate voltages two prominent leakage current mechanisms were invoked namely SE and FN tunneling which were similar to reported values elsewhere [26,28,29]. The I-V relationship for the SE emission can be expressed as…”

“…Two main conduction mechanisms were invoked to explain the current transport in TiO 2 thin films, i.e., SE and F-N tunneling [23,28,29]. The SE is a process occurring across the interface between a semiconductor (or metal) and an insulating film as a result of barrier lowering due to applied field.…”

“…The SE is a process occurring across the interface between a semiconductor (or metal) and an insulating film as a result of barrier lowering due to applied field. The leakage current is found to be dominated by the SE at a low electric field ( < 1 MV/cm) for both asdeposited and annealed samples, whereas PF effect appears only for the deposited samples at moderate electric field ( > 1 MV/cm) [26,28,29].…”

Spatial Distribution of Plasma Parameters in DC‐Energized Hollow Cathode Plasma Jet

“…For these reasons TiO 2 can be applied in the optical coatings designed for visible and infrared spectral ranges [23] that require material with high-refractive index. At normal or low pressure, stoichiometric TiO 2 is usually formed in thin films in amorphous, anatase or rutile phases.…”

Single‐phase TiO2formation by plasma oxidation of titanium thin films

“…This could be attributed to diffusion of Ti atoms in Si as the diffusivity of Ti in Si is higher than that of O in Si. [21] The SIMS depth profile confirms that the total thickness of the oxidized titanium film is about 95 nm. This oxide film shows uniform distribution of elemental composition with depth.…”