Perez Israel, Robertson Erin, Banerjee Parag, Henn-Lecordier Laurent, Son Sang Jun, Lee Sang Bok, Rubloff Gary W
Department of Materials Science and Engineering and Institute for Systems Research, University of Maryland, 2145 A. V. Williams Building, College Park, MD 20742-3285, USA.
Small. 2008 Aug;4(8):1223-32. doi: 10.1002/smll.200700815.
Nanotubes are fabricated by atomic layer deposition (ALD) into nanopore arrays created by anodic aluminum oxide (AAO). A transmission electron microscopy (TEM) methodology is developed and applied to quantify the ALD conformality in the nanopores (thickness as a function of depth), and the results are compared to existing models for ALD conformality. ALD HfO2 nanotubes formed in AAO templates are released by dissolution of the Al2O3, transferred to a grid, and imaged by TEM. An algorithm is devised to automate the quantification of nanotube wall thickness as a function of position along the central axis of the nanotube, by using a cylindrical model for the nanotube. Diffusion-limited depletion occurs in the lower portion of the nanotubes and is characterized by a linear slope of decreasing thickness. Experimentally recorded slopes match well with two simple models of ALD within nanopores presented in the literature. The TEM analysis technique provides a method for the rapid analysis of such nanostructures in general, and is also a means to efficiently quantify ALD profiles in nanostructures for a variety of nanodevice applications.
通过原子层沉积（ALD）将纳米管制备到由阳极氧化铝（AAO）形成的纳米孔阵列中。开发并应用了一种透射电子显微镜（TEM）方法来量化纳米孔中ALD的保形性（厚度随深度的变化），并将结果与现有的ALD保形性模型进行比较。通过溶解Al2O3将在AAO模板中形成的ALD HfO2纳米管释放出来，转移到网格上，并通过TEM成像。设计了一种算法，通过使用纳米管的圆柱模型来自动量化纳米管壁厚度沿纳米管中心轴位置的函数关系。扩散限制耗尽发生在纳米管的下部，其特征是厚度减小的线性斜率。实验记录的斜率与文献中提出的纳米孔内ALD的两个简单模型匹配良好。TEM分析技术总体上提供了一种快速分析此类纳米结构的方法，也是一种有效量化用于各种纳米器件应用的纳米结构中ALD分布的手段。
