Au诱导形成有序Si纳米孔阵列及其应用

以自组装聚苯乙烯小球(PS)单层膜为掩膜,利用Au对Si表面的催化氧化作用以及KOH溶液对单晶Si的各向异性腐蚀特性,在Si(100)面上制备了一系列尺寸小于100 nm有序可控的Si纳米孔阵列.扫描电镜(SEM)和原子力显微镜(AFM)等的测试结果显示:当PS小球溶液与甲醇溶液的体积比为9:11时,可形成大面积无缺陷的单层膜;但当体积比过大时,会导致类似双层膜结构的形成;而当体积比过小时,会诱导形成点缺陷和线缺陷.对PS小球及溅射Au处理过的Si晶片进行KOH溶液腐蚀,随着腐蚀时间变长,纳米孔的横向尺寸和深度增大,其形貌由圆形逐渐变为倒金字塔型,当腐蚀时间超过10 min,纳米孔阵列的有序性遭到破坏.采用离子束溅射技术在倒金字塔型纳米孔衬底上获得了有序Ge/Si纳米岛,而在圆形纳米孔衬底上获得了有序Ge/Si纳米环.进一步对有序Ge/Si纳米岛及纳米环的形成机理进行了解释.

Fabrication and application of ordered Si nanopore array induced by Au

Size-controlled Si nanopore array with a pore size less than 100 nm is fabricated on Si (100) substrates by using monolayer self-assembled and KOH anisotropic wet etching technique. Morphology and structure of the pores are characterized by SEM and AFM. Results show that a large area of defect-free polystyrene (PS) monolayer film can be obtained when the volume ratio of PS solution to methanol solution is 9:11. A larger volume ratio or a smaller volume ratio will induce similar bilayer structure and defects (point and line) in the PS film, respectively. The lateral size and depth of the nanopore will increase with the etching time, and its morphology will change from circular to inverted pyramid type gradually. But the orderly arranged structure will be destroyed as the etching time is over 10 min. On the other hand, ordered Ge/Si nanoislands and nanorings will be grown on nanopore-patterned Si (100) substrates (inverted pyramid and circular nanopores, respectively) by ion beam sputtering. In addition, reasonable interpretations have been proposed for the formation mechanism of the ordered Ge/Si nanostructure.
Keywords： Au-induced polystyrene spheres Si nanopore Ge/Si nano-array