Pulsed laser ablation and deposition of complex oxides
Pulsed laser ablation and deposition of complex oxides
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DOI：
10.1088/1742-6596/59/1/111
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发表时间：
2007-04
期刊：
影响因子：
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通讯作者：
T. Ohnishi;Takahisa Yamamoto;S. Meguro;H. Koinuma;M. Lippmaa
中科院分区：
文献类型：
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作者：
T. Ohnishi;Takahisa Yamamoto;S. Meguro;H. Koinuma;M. Lippmaa
研究了 SrTiO3 的脉冲激光烧蚀和沉积 (PLD) 工艺，作为开发典型复合氧化物的结构体等效外延薄膜生长技术的模型系统。沉积速率与激光注量测量结果表明，存在高于烧蚀阈值的第二个临界注量值。在临界值以下，烧蚀和沉积速率都是注量的线性函数并且与烧蚀点面积无关。在临界值以上，每单位烧蚀面积的沉积速率很大程度上取决于烧蚀点面积。同质外延SrTiO3薄膜只有在临界注量下生长时才具有精确的体晶格常数值，而当注量较高或较低时，会获得较大的晶格常数。成分分析表明晶格常数的增大与阳离子不平衡有关。这种临界激光注量对于体等效外延膜的生长至关重要，因此激光能量和烧蚀面积的精确测量对于可重复的膜生长至关重要。
The pulsed laser ablation and deposition (PLD) processes of SrTiO3 were studied as a model system for developing a technique for the growth of structurally bulk-equivalent epitaxial thin films of typical complex oxides. Deposition rate vs. laser fluence measurements showed that there is a second critical fluence value above the ablation threshold. Below the critical value, both the ablation and deposition rates are linear functions of the fluence and independent of the ablation spot area. Above the critical value, the deposition rate per unit ablation area depends strongly on the ablation spot area. Homoepitaxial SrTiO3 films possessed the exact bulk lattice constant value only when the films were grown at the critical fluence, whereas larger lattice constants were obtained if the fluence was either higher or lower. Composition analysis revealed that the enlargement of the lattice constant was related to cationic unbalance. This critical laser fluence is essential for the growth of bulk-equivalent epitaxial films, and therefore accurate measurement of laser energy and ablation area is vital for reproducible film growth.