Evaluation of the oxidation of TiO2 films during reactive evaporation of Ti3O5 and during exposure of the films to the atmosphere.
A surplus amount of oxygen is needed to produce titanium dioxide film by reactive electron-beam evaporation of Ti3O5. We investigated the ratio of the rates at which oxygen molecules and TiO(x) molecules impinge upon substrates at 25 degrees and 250 degrees C to produce TiO2 filmsthat show no optical absorption in the visible spectral region. On unheated substrates the ratio was 49, and at 250 degrees C it was 26, provided that the substrates had been exposed to air after being coated at the given substrate temperature. Higher ratios were required if the TiOs film was covered with a SiO2 film, which impeded further oxidation. Furthermore, the postdeposition oxidation behavior of these films was studied.
Linsbod
Robert
R
Umicore Materials R&D Laboratory, FL-9496 Balzers, Principality of Liechtenstein.
Ritter
Elmar
E
Leitner
Klaus
K