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The morphological and optical properties of indium tin oxide ͑ITO͒ thin films deposited by an ultralow-pressure dc magnetron sputtering ͑ULPS͒ method followed by postannealing treatment at 250°C are reported. The surface roughness of the film ͑R rms : 0.5 nm͒ deposited using ULPS was about 5 times lower than that of the film ͑R rms : 2.7 nm͒ sputtered using a pressure of 6.7 ϫ 10 −1 Pa. ITO thin films with a low resistivity of 3.7 ϫ 10 −4 ⍀ cm were also achieved using a continuous two-step deposition process, in which the initial layer was deposited using ULPS and then the final layer was deposited with a SP of 6.7 ϫ 10 −1 Pa, without the use of any other additional steps. Both the ULPS and continuous two-step deposition methods were found to be effective for producing ITO thin films with enhanced morphologies that make them suitable for use in display devices.Indium tin oxide ͑ITO͒ thin films are highly degenerate, widebandgap semiconductors ͑E g : 3.4-4.3 eV͒. They have a low electrical resistivity due to their high carrier concentration, and the location of their Fermi level is above the lower edge of the conduction band. 1-3 ITO films also exhibit a high level of transmission in the visible near-infrared regions of the electromagnetic spectrum. Due to these unique properties, ITO thin films have been widely studied for their potential use in the optoelectronics industry and display devices, such as solar-control windshield glass, solar cells, organic light-emitting displays ͑OLEDs͒, flexible display devices, and transparent, flexible electronic circuit boards. [3][4][5] Smooth surface morphology with high electrical conductivity is the crucial factor for the current driven devices such as OLEDs. So far, several methods have been employed to prepare ITO thin films. Examples include spray pyrolysis, reactive evaporation, pulsed laser deposition, conventional magnetron sputtering, cesium-ion-induced magnetron sputtering, and ion-beam assisted sputtering. 6-11 Among these deposition methods, magnetron sputtering is preferable, because it allows easy process control for the device structure and the production of display devices with large areas. However, one of the practical drawbacks of using sputtered ITO thin films for display device applications is their rough surface morphology. This makes them unsuitable for use as the semiconducting layer or transparent electrode of display devices. For example, the quality of the interface between the ITO electrode and the organic emitting layer is crucial to the performance of OLEDs. 12-15 Using a rough ITO layer as the anode may cause undesired electrical shorts or decrease the contact area between the emitting layers and the anode and even form bubbles to deteriorate the color quality and lifetime of the emitting area. 12,16 These functional properties of ITO thin films are strongly dependent on their microstructures, which are influenced by the deposition method and processing conditions used to make them.In this study, ITO thin films with smooth surface morphologies w...

The oxidation behavior of sputtered TiAlN thin-film barrier layers was studied by cross-section transmission electron microscopy. Bare 100-nm-thick TiAlN films on SiO2/Si began to oxidize from the surface after annealing in air for 10 min from about 550 °C. Annealing at 700 °C oxidized half of the layer thickness. A 100-nm-thick Pt overlayer on the barrier layer retarded macroscopic oxidation at 650 °C. However, a 10-nm-thick Pt overlayer accelerated oxidation as a result of the catalytic dissociation of O2 molecules to form O atoms, which oxidized the barrier layer at 550 °C to the same extent as without the thin Pt overlayer at 650 °C. The effects of other thin metal overlayers, such as Ru and Ir, were also investigated. Ru and Ir did not accelerate TiAlN oxidation due to the absence of catalytic activity.