Studying novel properties of complex oxides in nanoscale has become a popular research interest. Nanofabrication of complex oxides without damaging its intrinsic structure, however, is still challenging. In this work, we investigated the commonly used focused ion beam (FIB) technique for deep-patterning SrTiO 3 (STO) using Cr as a surface protective layer and found that it was insufficient in protecting STO against the damage caused by the FIB beam tail effect. We further developed a new method for effectively deep-patterning STO using FIB. Our approach adopted a hybrid surface layer of Cr and polymethyl methacrylate (PMMA) to protect the STO surface during the FIB milling process against the damage caused by the beam tail. This PMMA-assisted hybrid protective layer can effectively prevent the damage resulting from the energetic ion beam, as verified by high-resolution transmission electron microscopy characterization. It was found that PMMA is not spun off during the ...

中文翻译：

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聚焦离子束与PMMA辅助混合保护层对复杂氧化物的深层构图

在纳米尺度上研究复合氧化物的新特性已成为一个流行的研究兴趣。然而，在不破坏其固有结构的情况下纳米复合氧化物的制备仍然具有挑战性。在这项工作中，我们研究了常用的聚焦离子束（FIB）技术，以Cr为表面保护层对SrTiO 3（STO）进行深度图案化，发现该技术不足以保护STO免受FIB束尾造成的损害影响。我们进一步开发了一种使用FIB有效地对STO进行深度图案化的新方法。我们的方法采用了Cr和聚甲基丙烯酸甲酯（PMMA）的混合表面层，以保护FIB铣削过程中的STO表面免受束尾造成的损坏。这种由PMMA辅助的混合保护层可以有效地防止高能离子束造成的损坏，如通过高分辨率透射电子显微镜表征所证实的。发现在运行过程中没有分离出PMMA。