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

Fabrication and characterization of atomic-step-free silicon/oxide interface by controlling step arrangement

通过控制台阶排列制备和表征无原子台阶的硅/氧化物界面

基本信息

批准号：
12650029
负责人：
SUDOH Koichi
金额：
$ 2.3万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (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

项目摘要

We investigated the step dynamics on Si surfaces, the characterization method of Si/SiO_2 interface roughness by scanning tunneling microscopy (STM), and roughening of Si/SiO_2 interface during oxidations, in order to realize atomically flat and step free Si/SiO_2 interfaces. First, using high temperature STM, we studied the step dynamics during faceting transformation on vicinal Si(113) surfaces. We clarified the driving forces for step motion which causes considerable morphological changes in mesoscopic scale. We could interpret the observed coarsening of a step network in faceting transformation based on the continuum step model. We performed numerical simulations of a step network, demonstrating that the continuum step model can reproduce quantitatively the evolution of complicated step configurations. Second, we developed the characterization method of Si/SiO_2 interface roughness in sub-nanometer scale, using ultrahigh vacuum STM. We achieved STM observation of the interface morphology with atomic resolution, removing the SiO_2 overlayer by irradiating a field emission electron beam extracted from a STM tip at elevated temperatures. Using this method, we evaluated the interface roughness for chemical oxides formed by a wet chemical process and thermal oxides from semiconductor industrial processes. We showed that the wet chemical process roughen the interface morphology and the interface roughness of the thermal oxides is determined by the processes prior to the oxidation. Overall results obtained through this research indicate that control of the atomic steps on Si substrates to form atomically flat substrates is crucial, for fabrication of atomically flat Si/SiO_2 interfaces.

研究了Si表面的步进动力学、扫描隧道显微镜（STM）表征Si/SiO_2界面粗糙度的方法以及氧化过程中Si/SiO_2界面的粗化，以实现原子平坦和无步进的Si/SiO_2界面。首先，利用高温STM技术，研究了相邻Si（113）表面的刻面转化过程中的阶跃动力学。我们阐明了在介观尺度上引起相当大的形态变化的步进运动的驱动力。我们可以用连续阶跃模型来解释在分面变换中观察到的阶跃网络的粗化现象。对一个阶跃网络进行了数值模拟，结果表明连续阶跃模型可以定量再现复杂阶跃结构的演化过程。其次，利用超高真空STM技术，建立了亚纳米尺度的Si/SiO_2界面粗糙度表征方法。我们通过在高温下辐照从STM尖端提取的场发射电子束来去除SiO_2覆盖层，实现了具有原子分辨率的STM观察界面形态。利用这种方法，我们评估了湿化学过程形成的化学氧化物和半导体工业过程产生的热氧化物的界面粗糙度。我们发现，湿化学过程使界面形貌变得粗糙，热氧化物的界面粗糙度由氧化前的过程决定。通过本研究获得的总体结果表明，控制Si衬底上形成原子平面衬底的原子步骤对于制备原子平面Si/SiO_2界面至关重要。