WEIGHT-LOSS OF ALUMINA AND ZIRCONIA TARGETS DURING PLD

The weight loss due to laser-induced vaporization of alumina and zirco nia is investigated both theoretically and experimentally. To calculat e the weight loss of the target under laser irradiation a model is use d describing the laser-induced vaporization and the dynamics of the va pour/plasma state including the absorption of laser radiation. The wei ght loss is not an increasing function of the fluence over the whole r ange but has a local maximum due to absorption of laser radiation in t he plasma state. The energy deposited in the plasma state due to the a bsorption of laser radiation is calculated and compared to the weight loss data. Different pulse shapes of laser radiation influence the max imum value of the weight loss but leave the principal dependence on th e fluence unaltered. Furthermore, it is shown that increasing the back pressure from 0.06 to 100 mbar leads to considerably smaller weight l osses.