Evaluation of semiconductor/insulator interface structure by crystal model

通过晶体模型评估半导体/绝缘体界面结构

基本信息

批准号：
61460069
负责人：
OHDOMARI Iwao
金额：
$ 3.84万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1988
项目状态：
已结题

项目摘要

As a means of evaluating semiconductor/insulator interfaces, crystal modeling method is proposed. this crystal model consists of plastic balls and sticks representing atoms and bonds, respectively. inputting the coordinates of atoms based on the crystal model into computer, energy relaxation is carried out calculating keating energy. In order to evaluate an interface, the interface model is first constructed, then the keating of the interface-forming atoms is calculated which in turn gives informations about stability of the interface.As the result of the evaluation of low-index interfaces such as (100),(110) or (111), increasing energy was obtained in the order:(111), (110), (100). The stability of the interfaces decreased in the same order. Particularly, insulator/Si(100) substrate interface was evaluated in several ways, varying the shape of the interface. as the result, a pyramidal-shape interface surrounded by four (111) facets was found to be the most stable interface, which also … More agrees with the result of XPS measurement. Therefore, actual insulator/semiconductor interface is considered to form this type of shape.The interface was also evaluated by DV-Xa method, the energy of each orbital of interfaceforming atoms one of the molecular-orbital methods. Using this method, can be calculated and oxidation reaction at intefaces can be analyzed from electronic structure point of view. as the result, oxidation reaction was found to take place in the inner part of crystal instead of the interface itself.We have also examined the SOI structure formed by L-SPE technique, in which semiconductor crystal is formed on top an insulator layer, giving totally different characteristics to the interface from those of the oxidation interface. Tt the growth front, three-phase boundary region, consisting of c-Si, a-Si and a-SiO_2, is formed. The formation of microtwins is explained in terms of the distortion energy of atoms at the growth front. Also the formation of microtwins at c-Si/SiO_2 interface is explained by the stability of (111) interface. Furthermore, delayed crystal growth in the three-phase region, consisting of c-Si, a-Si and a-SiN, can be attributed to comparatively large lattice mismatch between c-Si and a-SiN. This result is a good agreement with modeling evaluation.As a conclusion, analysis based on modeling method is considered to be valid as far as its agreement with the experimental results is concerned. Less

作为评估半导体/绝缘体界面的一种方法，提出了由分别代表原子和键的塑料球和棒组成的晶体建模方法，将基于晶体模型的原子坐标输入计算机，进行能量弛豫。计算基化能为了评估界面，首先构建界面模型，然后计算界面形成原子的基化能，从而给出有关界面稳定性的信息。作为低指数评估的结果。接口如(100)、(110)或(111)，获得的能量依次为：(111)、(110)、(100)，界面稳定性以相同顺序降低。 ) ) 以多种方式评估基材界面，改变界面的形状，结果发现，由四个 (111) 小面包围的金字塔形界面是最稳定的界面。 ... 更多与XPS测量的结果一致，因此，实际的绝缘体/半导体界面被认为形成这种形状。该界面还通过DV-Xa方法进行了评估，界面形成分子之一的每个轨道的能量。 - 轨道法。使用该方法，可以从电子结构的角度计算和分析界面处的氧化反应，结果发现氧化反应发生在晶体内部而不是。我们还研究了通过L-SPE技术形成的SOI结构，其中半导体晶体形成在绝缘体层的顶部，从而使界面具有与氧化界面完全不同的特性，三个。形成由c-Si、a-Si 和a-SiO_2 组成的相边界区域。微孪晶的形成可以用生长前沿原子的畸变能来解释。 c-Si/SiO_2界面是通过(111)界面的稳定性来解释的，此外，由c-Si、a-Si和a-SiN组成的三相区域中晶体生长的延迟可归因于相对较大的晶格。 c-Si 和 a-SiN 之间的失配与模型评估吻合良好。总之，就其与实验结果的一致性而言，基于模型方法的分析被认为是有效的。