Annealing Treatment Method Research Articles

Enhanced optical properties of sol–gel derived TiO2 films using microwave irradiation

Thin films of TiO2 have been deposited on polished quartz substrates at room temperature by sol–gel dip coating technique followed two different annealing treatment methods. One set by conventional annealing at 600°C for 3h and second set exposure to microwave (2.45GHz) radiation at 600W power for 10min. X-ray diffraction and scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, UV–visible spectroscopy, techniques have been employed to characterize structural, morphological, compositional and optical properties of the microwave exposed and annealed films. Both microwave exposed and annealed films have shown the nanostructured growth of TiO2 anatase phase with grain size ranging from 10nm to 25nm. Due to decrease in the grain size there was a blue shift of Eg calculated in direct transition. Refractive index of the film annealed has shown higher value compared to microwave exposed films. Plausible mechanism for the formation of anatase phase of TiO2 on quartz substrates has also been discussed.

Analysis of the SiO 2 defects originated by phosphorus implantation in MOS structures

Medium-dose ion implantation is widely used in CMOS technology, however unwanted effects may occur when the doping ions are implanted through the thermally grown SiO 2 layer. We study the effect of the P + implantation in the dose range 10 11−10 13 cm −2 and annealing treatment methods on the carrier trapping centres concentration in bulk SiO 2 and the interface-state density at the SiO 2Si interface. Trapping kinetics analysis has been performed using photoinjection as a charging tool. We have found a dominant electron trapping centre with a capture cross section of (1–2)×10 −17 cm 2 and a second electron trapping centre with (1–3)×10 −16 cm 2. The density of the dominant trap has been found to be dependent on annealing treatment. These results are explained taking into account the damage introduced by the implantation process, which leads to the generation of carrier traps into the oxide. The initial interface state density rises with increasing dose and is also dependent upon the thermal treatment method. We also observe interface state generation after charge injection with a generation rate value higher than that usually found in nonimplanted structures, independently of implantation parameters.