聚苯乙烯纳米球模板和Si衬底的微结构随离子束轰击时间的演变规律  

Microstructure Evolution of Polystyrene Nanosphere Template andSi Substrate with the Exposure Time Under Ion Beam Bombardment

作　　者：李东泽 张明灵 杨杰 王茺[1,2] 杨宇 LI Dongze;ZHANG Mingling;YANG Jie;WANG Chong;YANG Yu(School of Materials Science and Engineering,Yunnan University,Kunming 650091,China;International Joint Research Center for Optoelectronic and Energy Materials,Yunnan University,Kunming 650091,China;School of Energy,Yunnan University,Kunming 650091,China)

机构地区：[1]云南大学材料科学与工程学院,昆明650091 [2]云南大学国家光电子能源材料国际联合研究中心,昆明650091 [3]云南大学能源研究院,昆明650091

出　　处：《材料导报》2020年第24期24155-24159,共5页Materials Reports

基　　金：国家自然科学基金(11504322,11564043);云南省应用基础研究计划面上项目(2019FB130,2016FB002);云南省教育厅科学研究基金项目(2019J0004);云南大学东陆中青年骨干教师培养项目。

摘　　要：使用离子束正入射轰击Si衬底上有序密排的聚苯乙烯(PS)纳米球模板,通过分析PS纳米球和Si衬底的微结构与离子束轰击时间的关系,研究了离子束的非选择性刻蚀对PS纳米球和Si衬底的刻蚀作用。实验结果表明:随着离子束轰击时间的延长,PS纳米球的直径和高度都呈单调递减的趋势,但是高度减小得更快。在这个过程中,PS纳米颗粒发生了由对称的圆形到非对称的圆形再到圆锥形的形貌转变,第一阶段的形变是离子束的各向异性刻蚀造成的,第二阶段可能与离子束的长时间轰击导致的热量积累有关。当PS纳米颗粒的尺寸和形貌发生变化的同时,Si衬底的微结构也在改变。当轰击时间为4 min时,在PS纳米颗粒下方观察到凸起的Si平台,随着时间的延长,Si平台的底端直径呈先稳定后减小的趋势,其高度则持续增加。同样,Si平台也经历着形貌的转变,第一阶段由圆柱形平台向截顶圆锥形平台转变,该形貌转变导致Si平台底端直径在轰击初期保持稳定;第二阶段发生在PS纳米颗粒消失后,由截顶圆锥形转变为圆锥形,形成了有序的Si纳米锥阵列,其直径在65~100 nm范围内。结合金属辅助化学刻蚀以及合适的非密排PS纳米颗粒模板,制备出有序的Si纳米线阵列,纳米线的直径为70~124 nm。这些结果为新型有序纳米材料的研制和应用提供了一定的基础及参考。Aself-assembled monolayer film of polystyrene(PS)nanospheres with close-packed arrays on Si substrate was bombarded at normal incidence by Ar+ion beam.The systematic study of non-selected etching of PS nanospheres and Si substrate were performed through the investigation on their microstructure evolution with the exposure time.With an increase in exposure time,the diameter and height of PS nanoparticles decreased monotonically,while the etching rate of nanoparticle height was higher.In this process,the shapes of PS nanoparticles were transformed from symmetrical sphere to asymmetric sphere and then cone.The reason for the first step of shape transition was the anisotropic etching of PS nanoparticles during physical sputtering process.For the second shape transition,it was attributed to the thermal energy accumulated gradually in a long-time bombardment of ion beam.At the same time,the surface structure of Si substrate was also changed.When the exposure time was 4 min,Si mesas with cylindrical morphology were observed under the PS nanoparticles.The change of the bottom diameter of Si mesas showed a trend of first stabilizing and then decreasing with the increase of exposure time.While,the height of Si mesas was continually enhanced.Simultaneously,the transition of Si mesa shapes also occurred.In the first step,cylindrical Si mesas were transformed to ones with truncated cone shape,leading to the stabilization of bottom diameter at the beginning of ion beam bombardment.Secondly,the shapes of Si mesas were transformed from truncated cone to cone after PS nanoparticles disappeared.And then ordered array of Si nanocones with a diameter range of 65—100 nm have been obtained.Combined with the suitable non-close-packed PS nanoparticle arrays and metal-assisted chemical etc-hing technology,ordered array of Si nanowires with a diameter range of 70—124 nm was prepared.These results lay a foundation and provide an alternative method for the development of novel ordered nanomaterials.

关 键 词：离子束刻蚀 纳米球刻蚀 有序阵列 SI纳米线 Si纳米锥 

分 类 号：TB383[一般工业技术—材料科学与工程]