Femtosecond laser ionization mass spectrometric analysis of layers grown by pulsed laser deposition
Femtosecond laser ionization mass spectrometric analysis of layers grown by pulsed laser deposition
复制标题
对脉冲激光沉积生长的层进行飞秒激光电离质谱分析
DOI：
10.1016/j.apsusc.2005.01.064
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发表时间：
2005
影响因子：
6.7
通讯作者：
J. Reif
中科院分区：
文献类型：
--
作者：
F. Costache;M. Ratzke;D. Wolfframm;J. Reif
飞秒激光诱导带电粒子发射和飞行时间质谱检测用于脉冲激光沉积（PLD）生长的多层金属氧化物半导体（MOS）结构的元素分析和深入分析：高k材料-氧化镨（Pr6O11）的薄膜沉积在硅（100）表面，并被铝接触层覆盖。在低入射影响下，发现了一种有效的单电荷正离子向大簇的发射。同时监测主离子产率与脉冲数表现出明显的反相关性，揭示了几个界面。这不仅表明层被分解，而且还检测到额外的层。表面形貌研究表明，在单脉冲或多脉冲照射下，在辐照区域产生局部孔和纳米颗粒。多个界面可以解释PLD层内的不均匀性和/或由于纳米颗粒形成的表面重排。我们证明，使用这种方法，可以实现纳米范围内的深度分辨率。讨论了飞秒激光烧蚀异质结构的基本机理。
Femtosecond laser-induced charged particle emission and detection by time-of-flight mass spectrometry are used for elemental analysis and in-depth profiling of multi-layered metal-oxide-semiconductor (MOS) structures grown by pulsed laser deposition (PLD): thin films of a high-k material – praseodymium oxide, Pr6O11– deposited on a silicon(100) surface and covered by an aluminum contact layer. An efficient emission of singly charged positive ions to large clusters was found at low incident fluence. The simultaneous monitoring of the main ion yields with the number of pulses exhibits pronounced anti-correlations, revealing several interfaces. This indicates not only that the layers were resolved but also additional layers were detected. Surface morphology investigation shows that, upon single- or multi-pulse exposure, localized holes and nano-particles were created on the irradiated area. The multiple interfaces may account for in-homogeneities within the PLD layer and/or a surface rearrangement due to the nano-particles formation. We demonstrate that, with this method, a depth resolution in the nanometer range can be achieved. Fundamental mechanisms of femtosecond laser ablation from hetero-structures are addressed.