Morphological Analysis of Ag Doped on TiO2/Ti Prepared via Anodizing and Thermal Oxidation Methods

In this work, we present the morphology analysis of TiO2/Ti prepared via anodizing and thermal oxidation (TO) methods and doped by Ag-TiO2 sol-gel nanocomposites through liquid phase deposition (LPD) technique. The comparative morphology of both semiconductors has been observed to inform the catalysis preparation for better morphology structures to the photocatalytic performance. Based on these results, we report that the TiO2/Ti prepared via anodizing method exhibits TiO2 nanotubes arrays (TNTAs) formed like honeycomb structures, while the TiO2/Ti TO (TTO) has diverse size structures. The neat arrangement of TNTAs has a larger surface area and pore volume than TTO structures, which can expose more adsorption and reaction sites, resulting in higher catalytic activity. Uniquely, both semiconductors, after coated by Ag-TiO2 sol-gel, show lamellar sediments covering the surface of TNTAs and TTO. We believe that the anodizing method is a good ability for photocatalysis compared with TTO in terms of small surface area and nanosize structures.

Fluorinated SiO2 Films For Interlayer Dielectrics In Quarter-Micron Ulsi Multilevel Interconnections

Fluorinated SiO2 films for use as interlayer dielectrics in ULSI multilevel interconnections are investigated. The interlayer dielectric film properties and their formation techniques have to meet the following requirements: (1) a low dielectric constant, (2) a high planarization capability, (3) a high capability for narrow gap filling, and (4) a low deposition temperature for low residual stress. To satisfy these requirements, three technologies have been investigated. They are: (i) a fluorinated SiO2 (SiOF) film by room temperature chemical vapor deposition (RTCVD-SiOF) using fluorotrialkoxysilane (FTAS) and pure water as gas sources, (ii) a room temperature liquid phase deposition (LPD) SiO2 film, and (iii) a fluorinated spin-on-glass (SOG) film by fluorotrialkoxysilane vapor treatment (FAST-SOG). The dielectric constant for SiO2 films can be reduced to 3.7 at 1 MHz by the RTCVD and LPD techniques. Although the FAST and RTCVD techniques cannot achieve full planarization, the LPD technique can achieve both global and local planarization because this technique has high capability for selective SiO2 film deposition. The RTCVD, FAST and LPD techniques have shown the possibility to reduce the film formation temperature to room temperature by catalytic reactions, resulting in low residual stress. Other properties of the RTCVD-SiOF, LPD-SiO2 and FAST-SOG films are good enough for the interlayer dielectric film application. The LPD-SiO2 film shows higher endurance properties to moisture than the RTCVD-SiOF and FAST-SOG films.