硅表面金属纳米团簇有序组装及电致迁移机制

项目名称： 硅表面金属纳米团簇有序组装及电致迁移机制

项目编号： No.10874114

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 孔向阳

作者单位： 上海交通大学

项目金额： 36万元

中文摘要： 我们分别研究了Si（111）与Pt(111)表面，在瞬态脉冲强电流作用下，台阶结构的演化，以及产生的表面应力所衍生的物理特性，取得如下研究结果: 1) 在超高真空环境中，利用瞬态脉冲电流，使Si（111）重构表面形成规则的直台阶，并发现在重构的台面上，沿垂直台阶方向存在着不同的应力区。这些应力区可以使硅重构表面产生选择性沉积。特别地，贵金属Pd纳米团簇在硅表面的不同应力区沉积时，可以组装成不同形貌图案。这充分反映了应力诱导的选择性吸附或不对称性沉积； 2) Pt（111）单晶薄膜在瞬态脉冲强电流作用下，可以形成螺旋形台阶结构。这种螺旋形台阶与螺旋位错有关，并在原子尺度表征了螺旋位错的形核与扩展模式。 此外，还研究了多层石墨烯的直台阶表面，理论上可以形成调制的能带结构，提出控制石墨烯台面宽度，研制能带可调的纳米器件的概念。

中文关键词： 硅表面;贵金属纳米团簇;电致迁移;选择性沉积;结构演化

英文摘要： We demonstrated that the structural evolutions of the vicinal surfaces of Si (111) and Pt(111) were subjected to the pulse flash current, responsible from the effects of electromigrating. There are some notable resutls as follows: 1) The regular step edges of the vicinal Si (111)-7×surface were fabricated by the sophisticated controlling of pulse flash current. It was found that the local stress patterns were induced by the intensive flash current, carring out the selective deposition in the vicinal surfaces. For a example, we provided an evidence on the selectivity of Pd clusters deposition on Si (111)-7×surfaces with local stress patterns.It is believed that the selective deposition of Pd nanoclusters open a new field to pattern the noble metal-based molecules on silicon for nanodevices. 2) A thin film of Pt (111) was subjected to the flash current treatment, giving rise to the regular helical step edges. The helical step edge is corresponding to the scew dislocation. The STM images show the original core of screw dislocation in atomistic lever as well as the clamb mode between the two vicinal surface. Besides, we proposed a modulated energy model for few layed graphenes with the vicinal surfaces. The vicinal surface of graphene provides a promising platform to realize the band-gap modulation engineering by means of the quantitative relation between the band-gap of graphene and the step width for nanodevice.

英文关键词： vicinal silicon susfacure;noble metal clusters; electromigrating; selective deposition;structural evolution