权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of atomically-controlled oxidation techniques for ultra-thin gate oxide films

超薄栅氧化膜原子控制氧化技术的发展

基本信息

批准号：
09555098
负责人：
ZAIMA Shigeaki
金额：
$ 8.13万
依托单位：
Nagoya 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 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09555098/
关键词：
Si SiOィイD22ィエD2 interface initial oxidation process of Si Structural relaxation Hydrogen atom impurity HREELS STM STS in-situ real-time observation 高分解能エネルギー損失分充法

项目摘要

We have clarified the effects of hydrogen and impurities on the initial oxidation processes of Si surfaces and the structural relaxation in SiOィイD22ィエD2 films using high-resolution electron energy loss spectroscopy (HREELS), scanning tunneling microscopy and scanning tunneling spectroscopy (STM/STS).The principal conclusions are shown below.(1) On a H-terminated Si (100) surface, it was found that Si-H bonds enhance the relaxation of Si-O-Si bonding structures by changing the bond angle. Moreover, Si-H bonds on the oxidized surface are more stable by the O adsorption on their two Si-Si back bonds. That is to say, the binding energy of the Si-H bonds on and in the oxide film is larger than that on Si surfaces.(2) In the case of the oxidation of pィイD1+ィエD1-Si (100) surfaces, the impurity concentration influences the relaxation of SiOィイD22ィエD2 structures. B atoms enhance the Si-O-Si structural relaxation. This phenomenon may be caused not by the exchange between Si atoms and B atoms but by the electronic effect such as Fermi level.(3) The strain accompanying the oxidation on H-terminated Si (111) surfaces is relaxed by enlarging the Si-O-Si bond angle. The relaxation is remarkably observed at an oxide thickness of 1ML, where the amount of Si-H species with two or three O atoms in the back bonds increases. As a result, surface Si atoms with a Si-H bond are lifted up.(4) On the pィイD1+ィエD1-Si (100) surface, specific structures formed by surface-segregated B atoms are observed and it was found out that there are two kind of structures. B atoms stabilize an O adsorption site, which is unstable on a Si surface with a low impurity concentration. This finding strongly suggests that the O adsorption site is controllable by changing the surface strain with the B concentration.

利用高分辨电子能量损失谱（HREELS）、扫描隧道显微镜和扫描隧道谱（STM/STS）研究了氢和杂质对Si表面初始氧化过程和SiO_xD_（22）O_xD_（22）薄膜结构弛豫的影响。(1)在H端Si（100）表面上，发现Si-H键通过改变键角而增强Si-O-Si键结构的弛豫。此外，氧化表面上的Si-H键由于O吸附在其两个Si-Si背键上而更加稳定。也就是说，氧化膜上和氧化膜中的Si-H键的结合能大于Si表面上的结合能。(2)在p型Si_（100）表面氧化的情况下，杂质浓度影响SiO_（100）D_22 → SiO_（100）D_2结构的弛豫。B原子增强了Si-O-Si结构弛豫。这种现象可能不是由于Si原子和B原子之间的交换引起的，而是由于费米能级等电子效应引起的。(3)通过增大Si-O-Si键角，缓和了H端Si（111）表面氧化产生的应变。当氧化层厚度为1 ML时，背键中含有两个或三个氧原子的Si-H物种的数量增加，弛豫现象明显。结果，具有Si-H键的表面Si原子被抬起。(4)在p型Si_（100）表面上，观察到由表面偏聚的B原子形成的特殊结构，发现存在两种结构。B原子使O吸附位置稳定，该O吸附位置在具有低杂质浓度的Si表面上不稳定。这一发现有力地表明，O吸附位点是可控的，通过改变表面应变与B浓度。