Surface Modification of Hydrogen-Terminated Silicon Substrate using Extra-Low Energy Electron Beam

使用超低能电子束对氢封端硅衬底进行表面改性

基本信息

批准号：
09450017
负责人：
OURA Kenjiro
金额：
$ 10.05万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Electron-stimulated desorption (ESD) of hydrogen from hydrogen-terminated Si substrates is expected for versatile applications in nano-fabrication in connection with surface modifications with use of electron beam patterning. In the electron beam patterning of hydrogen-terminated substrates, e-beam with high energy of 20-50 keV is usually used, which causes thermal desorption of hydrogen as well as ESD.In order to suppress the thermal effect by e-beam and to realize local removal of surface hydrogen caused only by ESD, it is necessary to adopt extra-low energy electrons with 10 eV order. For this purpose, it is of great importance to elucidate the mechanism of ESD in the extra-low energy region. The purpose of this research project is to fundamentally elucidate the surface modification process of hydrogen-terminated Si substrates on atomic scale.With use of newly introduced low-energy electron gun, we performed in-situ observation of ESD processes of hydrogen from hydrogen-terminated Si(100) and Ge/Si( 100) surfaces using time-of-flight elastic recoil detection analysis (TOF-ERDA), and obtained the electron energy dependence of ESD cross-section of hydrogen in the extra-low energy region. The result worthy of special mention was that we obtained interesting findings on the mechanism of ESD of hydrogen from hydrogen-terminated Si(l00) ; namely, (1) threshold electron energy of ESD was about 23 eV, and (2) the mechanism of ESD was related to the core band excitation in which Auger decay of a core hole occurred in a covalent Si-H bond, leading to a multi-hole final state in the bonding orbital and desorption of H.

来自氢封端硅衬底的氢的电子刺激解吸（ESD）有望在与使用电子束图案化进行表面修饰相关的纳米制造中得到广泛应用。在氢端基衬底的电子束图形化中，通常使用20-50keV高能量的电子束，这会引起氢的热脱附以及ESD。为了抑制电子束的热效应，要实现仅由ESD引起的表面氢的局部去除，需要采用10 eV量级的超低能电子。为此，阐明超低能量区域的 ESD 机制具有重要意义。本研究项目的目的是从原子尺度上从根本上阐明氢端硅衬底的表面改性过程。利用新引进的低能电子枪，对氢端硅衬底上的氢的ESD过程进行了原位观察。采用飞行时间弹性反冲检测分析（TOF-ERDA）对Si（100）和Ge/Si（100）表面进行分析，得到超低能量下氢的ESD截面的电子能量依赖性地区。值得特别一提的结果是，我们获得了关于氢封端的 Si(l00) 的氢的 ESD 机理的有趣发现；即，（1）ESD的阈值电子能量约为23 eV，（2）ESD的机制与核心带激发有关，其中核心空穴的俄歇衰变发生在共价Si-H键中，导致H的成键轨道和解吸中的多孔最终状态。