Phase transition from Langmuir-type adsorption to two-dimensional oxide island growth during oxidation on Si(001) surface
Phase transition from Langmuir-type adsorption to two-dimensional oxide island growth during oxidation on Si(001) surface
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DOI：
10.1016/s0169-4332(03)00501-4
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发表时间：
2003-06-30
影响因子：
6.7
通讯作者：
Kawawa, T
中科院分区：
文献类型：
--
作者：
Takakuwa, Y;Ishida, F;Kawawa, T
利用实时俄歇电子能谱（AES）结合反射式高能电子衍射（RHEED）研究了Si（001）表面初始氧化过程中从Langmuir型吸附到二维氧化岛生长的相变.对O-KLL俄歇电子强度仪测得的氧吸收曲线进行曲线拟合分析，发现在630 ℃附近发生了急剧的相变，氧化物岛的二维生长完成后没有发生氧化，而氧化物在界面处以Langmuir型吸附逐渐生长。观察到，尽管在616 ℃下生长的非常薄的氧化物层的厚度几乎相同，但其比在653 ℃下生长的氧化物层更容易分解。此外，半级斑点之间的RHEED强度比表明，表面的蚀刻突然开始在相变温度类似于630 ℃。相变的陡度，用表面反应模型综合解释了Si（001）2x 1表面上O-2吸附从无势垒吸附转变为二聚体背键的Langmuir型吸附到形成脱附前驱体SiO* 的过程，并对两种氧化模式下SiO * 脱附的突然开始和界面氧化分解的差异进行了解释。与用于2D氧化物岛生长的二聚体空位成对，并且SiO* 的聚结导致氧化物岛的成核和2D生长。(C)2003 Elsevier Science B. V.保留所有权利。
The phase transition from Langmuir-type adsorption to two-dimensional (2D) oxide island growth during initial oxidation on the Si(001) surface was investigated by real-time Auger electron spectroscopy (AES) combined with reflection high-energy electron diffraction (RHEED). Curve-fitting analysis of the oxygen uptake curve obtained by O-KLL Auger electron intensity revealed that the phase transition occurs steeply at similar to630 degreesC and no oxidation occurs after completion of 2D growth of oxide islands, whereas oxides grows gradually at the interface following Langmuir-type adsorption. It was observed that the very thin oxide layer grown at 616 degreesC is more easily decomposed than that grown at 653 degreesC in spite of almost the same thickness. Furthermore, the RHEED intensity ratio between half-order spots indicated that etching of the surface starts suddenly just at the phase transition temperature of similar to630 degreesC. The steepness of the phase transition, the sudden start of SiO desorption and the difference in the interfacial oxidation and decomposition between two oxidation schemes are comprehensively interpreted using a surface reaction model in which O-2 adsorption on the Si(001) 2 x 1 surface changes drastically from barrier-less adsorption into dimer backbonds for Langmuir-type adsorption to formation of desorption precursor SiO* in pairs with dimer vacancies for 2D oxide island growth, and coalescence of SiO* leads to nucleation and 2D growth of oxide islands. (C) 2003 Elsevier Science B.V. All rights reserved.