Department of Physics, Ewha Womans University, Seoul, Republic of Korea.
Ultramicroscopy. 2010 May;110(6):737-40. doi: 10.1016/j.ultramic.2010.02.042. Epub 2010 Mar 10.
We report fabrication of Ti metal nanodot arrays by scanning probe microscopic indentation. A thin poly-methylmethacrylate (PMMA) layer was spin-coated on Si substrates with thickness of 70nm. Nanometer-size pore arrays were formed by indenting the PMMA layer using a cantilever of a scanning probe microscope. Protuberances with irregular boundaries appeared during the indentation process. Control of approach and pulling-out speed during indentation was able to dispose of the protrusions. Ti metal films were deposited on the patterned PMMA layers by a radio-frequency sputtering method and subsequently lifted off to obtain metal nanodot arrays. The fabricated metal nanodot arrays have 200nm of diameter and 500nm of interdistance, which corresponds to a density of 4x10(8)/cm(2). Scanning probe-based measurement of current-voltage (I-V) behaviors for a single Ti metal nanodot showed asymmetric characteristics. Applying external bias is likely to induce oxidation of Ti metal, since the conductance decreased and volume change of the dots was observed. I-V behaviors of Ti metal nanodots by conventional e-beam lithography were also characterized for comparison.
我们报告了通过扫描探针显微压痕法制备 Ti 金属纳米点阵列。在厚度为 70nm 的 Si 衬底上旋涂一层薄的聚甲基丙烯酸甲酯（PMMA）层。通过使用扫描探针显微镜的悬臂将 PMMA 层压痕，形成纳米级孔阵列。在压痕过程中出现了具有不规则边界的突起。在压痕过程中控制接近和拔出速度能够处理这些突起。通过射频溅射法在图案化的 PMMA 层上沉积 Ti 金属薄膜，然后将其剥离以获得金属纳米点阵列。所制备的金属纳米点阵列的直径为 200nm，间距为 500nm，对应的密度为 4x10(8)/cm(2)。对单个 Ti 金属纳米点的基于扫描探针的电流-电压（I-V）行为进行了测量，结果表明其具有不对称特性。施加外部偏压可能会导致 Ti 金属的氧化，因为观察到电导降低和点的体积变化。为了进行比较，还对通过传统电子束光刻制备的 Ti 金属纳米点的 I-V 行为进行了表征。
