Thin films of Ta2O5 have been deposited on quartz and silicon substrates by
532-nm (Nd:YAG) pulsed laser deposition (PLD) in various O-2 as environmen
ts. The influence of the deposition parameters, such as oxygen pressure, su
bstrate temperature and annealing under UV irradiation using a 172-nm excim
er lamp, on the properties of the grown films, has been studied. The refrac
tive index of the films increases with increasing pressure of O-2. X-ray di
ffraction measurements show that the as-deposited films are amorphous at te
mperatures below 500 degrees C and possess orthorhombic (beta-Ta2O5) crysta
l structure at temperatures above 600 degrees C. The optical properties det
ermined by UV spectrophotometry also strongly depend on the deposition para
meters. At O-2 pressures above 0.15 mbar, the refractive index of the films
was about 2.12 which is close to the bulk Ta2O5 value of 2.2. Optical tran
smittance around 85% in the visible region of the spectrum was obtained at
an oxygen pressure of 0.2 mbar, (C) 1999 Elsevier Science B.V. All rights r
eserved.