Formation mechanism of silicon surface nanoholes

硅表面纳米孔的形成机制

• 批准号: 10305006
• 负责人: TAKEDA Seiji
• 金额: $ 25.86万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10305006/
• 关键词: silicon; surface; nanostructures; electron irradiation; point defects; ナノストラクチュア

The aim of this research project is to elucidate the formation mechanism of silicon surface nanoholes, which are introduced on silicon surface by high energy electron irradiation. Preliminary studies on the formation of nanoholes were carried out soon after the finding of surface nanoholes by the principal investigator of the research project. Supported by the grant, the systematic studies were made possible by means of transmission electron microscopy and scanning tunneling microscopy. Based on the substantial experimental data along with computer simulation, we have shown that the formation process of surface nanoholes is classified in the three stages. 1) The minimum electron energy needed for the formation of nanoholes has been determined to be 30keV.This shows that, as the primary event of the nanohole formation, single Si atoms on a surface are sputtered out, leaving surface vacancies behind. 2) Under electron irradiation, surface vacancies can migrate athermaly as well as thermally in the wide temperature range from 4 to 500K.3) Nanoholes are gradually excavated along the direction of ongoing electrons with the increase of electron dose. The peculiar phenomenon is accounted for by the anisotropic diffusion of surface vacancies via the momentum transfer from electrons to Si atoms located on the wall of nanohoels. The present study has clarified that the dynamic nature of atoms on surface at the states far from the equilibrium, which has been much less described so far.During the experiments which were proposed in the project, we have found a new phenomenon that electron irradiation renders crystalline silicon to amorphous silicon. The mechanism of the amorphization is also accounted for by the clustering of point defects under electron irradiation.The present study will be a basis for fabrication of nanostructures and Si-based microelectronic devices, since an electron beam can be focused on an area smaller than nano-meters and scanned easily.

该研究项目的目的是阐明硅表面纳米骨的形成机理，这些机理是通过高能电子照射在硅表面引入的。研究项目的主要研究者发现表面纳米骨后不久就进行了有关纳米峰形成的初步研究。在赠款的支持下，通过透射电子显微镜和扫描隧道显微镜使系统研究成为可能。基于大量的实验数据以及计算机模拟，我们表明表面纳米骨的形成过程在三个阶段分类。 1）已确定形成纳米骨所需的最小电子能量为30kev。这表明，作为纳米霍尔形成的主要事件，表面上的单个Si原子被溅射出来，使表面空位留在后面。 2）在电子辐照下，表面空缺可以在4至500k的宽温度范围内迁移雅典和热迁移。3）纳米霍尔斯随着电子剂量的增加而沿着正在进行的电子方向逐渐挖掘出来。特殊的现象是通过从电子到位于纳米烷壁上的SI原子的动量转移的各向异性扩散来解释的。本研究澄清说，远离平衡的状态的原子的动态性质，到目前为止的描述得多得多。在项目中提出的实验中，我们发现了一种新现象，该现象使电子辐照使晶体硅晶体硅从无晶的硅。还通过电子辐照下的点缺陷的聚类来解释非晶化的机制。本研究将是制造纳米结构和基于SI的微电动器件的基础，因为电子束可以集中在小于纳米仪的区域上，并轻松扫描。

项目成果

N.Ozaki,Y.Ohno,M,Tanbara,D.Hamada,J.Yamasaki & S.Takada: "Observation of silicon surface nanoholes by scanning tunneling microscopy"Surface Science. (accepted for publication).

N.Ozaki,Y.Ohno,M,Tanbara,D.Hamada,J.Yamasaki

N.Aki,Y.Ohno,H.Kohno & S.Takada: "Formation of microcracks in cubic boron nitride"PhiBos.Mag.A59. A59. 2694-2699 (2000)

N.Aki,Y.Ohno,H.Kohno

H.Kohno,T.Iwasaki & S.Takada: "Metal-mediated growth of alternate semiconductor-insulator nanostructures"Solid State Communications. 116. 591-594 (2000)

H·河野,T·岩崎

H.Kohno and S.Takeda: "Periodic instability in growth of chairs of crystalline-silicon nanospheres"J.Crys.Grocoth. 216. 185-191 (2000)

H.Kohno 和 S.Takeda：“晶体硅纳米球椅生长的周期性不稳定”J.Crys.Grocoth。

S.Takeda and J.Yamasaki: "Amorphigathe in silicon by electron irradiation"Phys.Rov.Lett.. 83. 320-323 (1999)

S.Takeda 和 J.Yamasaki：“通过电子辐照在硅中形成无定形”Phys.Rov.Lett.. 83. 320-323 (1999)