角分辨飞行时间法研究紫外激光烧蚀Ta_2O_5的反应

An Angle-resolved TOF Study on the UV Laser Ablation of Tantalum Oxide

利用角分辨的飞行时间法研究了355nm脉冲激光烧蚀Ta2O5的反应．由四极质谱测得的烧蚀产物除了O,Ta，Tao和TaO2中性碎片外，在较高激光能量密度时还有O+，Ta+，TaO+，TaO离子碎片。它们的飞行时间（TOF）谱可以用多组分带质心速度的Maxwell-Bolztmaun分布函数较好地拟合，原生离子碎片的平均动能与激光能量密度无关．烧蚀产物中原生离子和中性粒子的角分布可以分别用αcosnθ（n≈26）和αcosθ＋bcosnθ（n≈27）函数拟合。此外，对紫外脉冲激光烧触Ta2O5的机理进行了讨论．

UV pulsed laser ablation of tantalum oxide at 355nm has been investigated by angleresolved time-of-flight quadrupole mass spectrometric method. The measured TOF spectra show that the main ablation neutral products are O, Ta, TaO and TaO2, and the corresponding ionic species are observed with increasing the laser fluence. Their TOF spectra can be fitted by multicomponent Maxwell-Bolztmann distributions with a center-of-mass velocity, and the translational energies of the ionic species are independent on the laser fluence under our experimental conditions. The angular distributions of the ionic and neutral ablation products can be fitted by the expressions of acosnθ(n＝26 ) and acosθ+4cosnθ (n＝27), respectively. Possible mechanisms for the production of these species in the UV laser ablation process are discussed.