In-situ Observation of Atomic Layr Epitaxy by Photoelectron Oscillation

光电子振荡原位观察原子层外延

• 批准号: 07650001
• 负责人: ENTA Yoshiharu
• 金额: $ 1.6万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650001/
• 关键词: Si(100); epitaxial growth; photoelectron spectroscopy; oscillation; in-situ observation; real-time measurement; RHEED; photoelectron oscillation; Si (100)

Recently, we carried out real-time ultraviolet photoelectron spectroscopy (UPS) measurements using synchrotron radiation during Si epitaxial growth on a Si(100) surface by Si_2H_6 gas-source molecular-beam epitaxy (GSMBE), and observed that the normal emission intensity of the photoelectrons from the serface states on Si(100)2x1 oscillates periodically. We interpreted this photoelectron-intensity oscillation (PIO) as due to Si layr-by-layr growth, and showed a possibility of monitoring the epitaxial growth process by PIO.The purpose of this study is to elucidate the origin of PIO.The obtained results are described as follows.1.PIO and reflection high-energy electron diffraction (RHEED) oscillation were simulated by the Monte Carlo technique. PIO was reproduced well by a model assuming an alternation between the 2x1 and the 1x2 surface reconstructions during growth. The results of the simulation also showed that PIO appears under wide ranges of the temperature and of the growth rate com … More pared with those for RHEED oscillation.2.The model in result 1 consequently suggests that the period of the oscillations correspond to two monolayr growth. To confirm this relation, RHEED oscillation were measured during GSMBE,under identical growth conditions with those used for PIO observations. The oscillation period at the half-order diffraction spots agreed well with that of PIO at various Si_2H_6 pressures, providing a direct support for the above interpretation for the origin of PIO.3.Initial thermal oxidation processes by dry oxygen within the first monolaver on Si(100) have been investigated by real-time UPS.For oxidation temperatures at 350-600ﾟC the time evolution of the O 2p state intensity, a good measure for the amount of the formed oxide, presented a Langmuir-type adsorption behavior. For temperatures above 700ﾟC, the evolution was well described by a model assuming a twodimensional island growth. A unified explanation is given for this difference in the oxidation kinetics by considering the presence of the oxide decomposition process in the higher temperature region. Less

最近，我们在Si_2H_6气态源分子束外延(GSMBE)的Si(100)表面上用同步辐射进行了实时紫外光电子能谱(UPS)测量，观察到从Si(100)2x1面态发出的光电子的法向发射强度周期性地振荡。我们解释了这种光电子强度振荡(PIO)是由于Si的逐层生长引起的，并显示了用PIO监测外延生长过程的可能性。本研究的目的是阐明PIO的来源。主要结果如下：1.用蒙特卡罗方法模拟了PIO和反射高能电子衍射(RHEED)振荡。通过假设生长过程中2x1和1x2表面重建之间的交替的模型，Pio被很好地再现。模拟结果还表明，在较宽的温度范围和生长速率范围内，…都出现了PIO现象结果1中的模型表明，振荡的周期对应于两个单层增长。为了证实这一关系，在GSMBE过程中测量了RHEED振荡，在与PIO观测相同的生长条件下进行了测量。在不同的Si_2H_6压力下，半级衍射点的振荡周期与PIO的振荡周期很好地吻合，为上述PIO起源的解释提供了直接支持。3.用实时UPS研究了在Si(100)表面上第一个单晶格内干氧的初始热氧化过程。在350-600ﾟC的氧化温度下，O2态强度的时间演化呈现朗缪尔型吸附行为，这是一个很好地衡量生成氧化物量的指标。对于700ﾟC以上的温度，这一演变可以用一个假设为二维岛生长的模型很好地描述。通过考虑高温区氧化物分解过程的存在，对氧化动力学的这种差异给出了统一的解释。较少

项目成果

Y.Enta: "Growth kinetics of thermal oxidation process on Si(100) by real time ultraviolet photoelectron spectroscopy" Applied Surface Science. vol.100/101. 449-453 (1996)

Y.Enta：“通过实时紫外光电子能谱研究 Si(100) 热氧化过程的生长动力学”应用表面科学。

Y. Enta et al.: "Band-dispersion-originated photoelectron intensity oscillations during Si epitaxial growth on Si (100)" Journal of Electron Spectroscopy. (印刷中). (1996)

Y. Enta 等人：“Si (100) 上 Si 外延生长过程中的能带色散引发的光电子强度振荡”《电子能谱杂志》（1996 年出版）。

Y.Enta: "Band-dispersion-originated photoelectron intensity oscillations during Si epitaxial growth on Si(100)2x1 surface" Photon Factory Activity Report. vol.13. (1995)

Y.Enta：“Si(100)2x1 表面上 Si 外延生长过程中的带色散引发的光电子强度振荡”光子工厂活动报告。

Y.Enta: "A comparison between UPS and RHEED intensity oscillations during Si epitaxial growth on Si(100)" Journal of Vacuum Science and Technology. (in press). (1997)

Y.Enta：“Si(100) 上 Si 外延生长过程中 UPS 和 RHEED 强度振荡的比较”真空科学与技术杂志。

Y.Enta: "Band-dispersion-originated photoelectron intensity oscillations during Si epitaxial growth on Si(100)" Journal of Electron Spectroscopy. 80. 173-176 (1996)

Y.Enta：“Si(100) 上 Si 外延生长过程中的能带色散引发的光电子强度振荡”电子能谱杂志。