A Review of 1064-nm Damage Tests of Electron-Beam Deposited Ta 2 O 5 /SiO 2 Antireflection Coatings
Damage tests of Ta 2 O 5 /SiO 2 antireflection films deposited under a variety of conditions showed that thresholds of films deposited at 175 C were greater than thresholds of films deposited at either 250 C or 325 C. Deposition at high rate and low oxygen pressure produced highly absorptive films with low thresholds. Thresholds did not correlate with film reflectivity or net stress in the films, and correlated with film absorption only when the film absorption was greater than 10 4 ppm. Baking the films for four hours at 400 C reduced film absorption, altered net film stress, and produced an increase in the average damage threshold.