In-situ observation of thermal oxidation on the Si surface by RHEED-AES CL

RHEED-AES CL 原位观察 Si 表面热氧化

基本信息

批准号：
12650026
负责人：
TAKAKUWA Yuji
金额：
$ 2.3万
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：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650026/
关键词：
Si thermal oxidation RHEED AES Emission of Si atoms Interface strain Real-time monitoring Surface reaction model Gate insulator film RHEED AES シリコン酸化過程カソードルミネッセンス「その場」観察

项目摘要

The initial stage of thermal oxidation on the Si(001) surface with dry O_2 was investigated by a realtime monitoring method of Auger electron spectroscopy combined with reflection high energy electron diffraction (RHEED-AES) in order to clarify the growth model of very thin SiO_2 layers for the gate insulator of metal-oxide-semiconductor field effect transistor (MOSFET). The RHEED-AES method made it possible to measure simultaneously the oxide coverage and etching rate during Si thermal oxidation. The time evolution of O KLL Auger electron intensity discriminated clearly three oxidation schemes of Langmuir-type oxidation, two-dimensional oxide island growth and active oxidation, and gave a phase diagram of the oxidation scheme as a function of O_2 pressure and temperature. In the Langmuir-type oxidation region, emission of Si atoms from oxides was suggested by the time evolution of half-order RHED spot intensities, which was interpreted in terms of the interfacial strain due to volume expansion associated with oxidation. In the two-dimensional oxide island growth and active oxidation region, the half-order RHEED spot intensities showed a oscillatory behavior, the oscillation period of which was independent of temperature, oxide coverage and oxidation scheme, but decreased in proportion to O_2 pressure. This means that the etching reaction is not rate-limited by SiO desorption but by O_2 adsorption. Based on the experimental results, a surface reaction model of two-dimensional oxide island growth was proposed, in which collisions between desorption precursors of SiO migrating on the surface lead to nucleation and growth of oxide islands and therefore etching of the surface originates from oxide growth as well as SiO desorption. As a result, it was concluded that the emission and surface migration of Si atoms should be considered in the surface reaction model of all oxidation schemes appearing at the initial Si thermal oxidation.

通过实时监控方法的实时监测方法与反射高能电子衍射（RHEED-AES）相结合，研究了带有干o_2的SI（001）表面热氧化的初始阶段，以阐明非常薄的SIO_2层的生长模型，以使其非常薄的SIO_2层用于金属氧化物 - 氧化物 - 氧化物 - 氧化物 - 氧化型透射率效应的闸门绝缘。 Rheed-AES方法使得在SI热氧化过程中同时测量氧化物覆盖率和蚀刻速率。 O KLL螺旋螺旋电子强度的时间演变清楚地歧视了Langmuir型氧化，二维氧化物岛的生长和主动氧化的三种氧化方案，并给出了氧化方案的相图作为O_2压力和温度的函数。在Langmuir-type氧化区域中，通过半阶Rhed斑点强度的时间演化提出了Si原子的发射，这是根据与氧化相关的体积膨胀而解释的。在二维氧化物岛的生长和主动氧化区域中，半阶Rheed斑点强度显示出振荡行为，其振荡周期与温度，氧化物覆盖率和氧化方案无关，但与O_2压力成本下降。这意味着蚀刻反应不是通过SIO解吸的速率限制，而是通过O_2吸附。根据实验结果，提出了二维氧化物岛生长的表面反应模型，其中SIO在表面迁移的SIO的解吸前体之间的碰撞导致氧化物岛的成核和生长，因此表面蚀刻的是氧化物的生长以及SIO吸收。结果，得出的结论是，在初始Si热氧化处出现的所有氧化方案的表面反应模型中，应考虑SI原子的发射和表面迁移。