Investigation of the PECVD TiO2-Si(100) interface

Continuous wave (CW) and equivalently powered, pulsed radio frequency plasmas were used to deposit thin films of titanium dioxide on to Si(1 0 0) substrates. Plasmas were created by feeding oxygen gas through the coil region, TIP was introduced downstream from the coil region. These films have been characterized using XPS, SEM and AES. Results show high quality amorphous films were produced with some carbon incorporation. Sputtering the TiO2 films to the Si interface results in the formation of TiSi2. Annealing the films in vacuum at 900 degreesC results in the reduction of TiO2 to Ti2O3 at the interfacial region, while Si is oxidized to SiOx. Upon annealing at 950 degreesC, further reduction of the TiO2 film was noted to include TiO. The 950 degreesC film is partially reoxidized upon exposure to atmosphere. SEM of the TiO2 film surfaces showed the as deposited films were smooth and structureless and remained so even after being annealed at 850 degreesC. Annealing at 950 degreesC, however, caused the surface to become very rough, resulting in the rupturing of the TiO2 surface, thus exposing areas of the underlying Si/SiO2 substrate. (C) 2004 Elsevier B.V. All rights reserved.