Delta layer formation of silver nanoparticles in thin silicon dioxide film by negative ion implantation
Delta layer formation of silver nanoparticles in thin silicon dioxide film by negative ion implantation
复制标题
负离子注入在二氧化硅薄膜中形成银纳米颗粒的Delta层
DOI：
10.1016/j.surfcoat.2004.08.088
复制
发表时间：
2005
影响因子：
5.4
通讯作者：
J. Ishikawa
中科院分区：
文献类型：
--
作者：
H. Tsuji;N. Arai;T. Matsumoto;K. Ueno;K. Adachi;H. Kotaki;Y. Gotoh;J. Ishikawa
研究了两种通过负离子注入在δ层中一定深度分布纳米粒子的形成方法。这种孤立金属纳米粒子的δ层形成是在非常薄的栅极氧化膜中所期望的，其厚度小于10纳米，用于开发使用纳米粒子作为库仑封锁的非常小的电容的单电子器件。我们尝试了两种方法，即在硅衬底上热生长的 SiO2 薄膜中注入金属负离子并进行后退火，以实现 (1) 在 SiO2 薄膜的表面区域形成金纳米粒子的 Delta 层，以及 (2) 在 SiO2 薄膜的底部区域形成银纳米粒子的 Delta 层。前者采用低能量金负离子注入，在低于900℃退火时形成的纳米颗粒的深度分布取决于注入原子的深度偏差。通过 1 keV 的 Au 负离子注入和 900 °C 的退火，在表面下方获得了直径为 4-8 nm 的几乎 δ 层的 Au 纳米颗粒。后者采用 10 keV、1×1015ions/cm2、25 nm 厚的 SiO2/Si 银负离子注入，并在 700 °C 下退火，直径为 6-8 nm 的 Ag 纳米粒子在 SiO2 底部区域的 δ 层中以相同深度排列，距边界 2 nm。
Two formation methods of nanoparticles distributed at a certain depth in a delta layer by negative ion implantation were investigated. Such delta layer formation of isolated metal nanoparticles is desired in a very thin gate oxide film, with thickness of less than 10 nm for the development of a single electron device using nanoparticles as very small capacitance for Coulomb blockade. We have tried two methods by metal negative ion implantation in a thermally grown SiO2film on Si substrate and postannealing for (1) a delta layer formation of gold nanoparticles in the surface region of SiO2film, and for (2) a delta layer formation of silver nanoparticles in the bottom region of SiO2film. In the former with gold negative ion implantation with a low energy, the depth distribution of nanoparticles formed at annealing at less than 900 °C depended on depth deviation of implanted atoms. The almost delta layer of Au nanoparticles with diameters of 4–8 nm was obtained just under the surface by Au negative ion implantation at 1 keV and annealing at 900 °C. In the latter with silver negative ion implantation at 10 keV, 1×1015ions/cm2, 25-nm-thick SiO2/Si, and annealing at 700 °C, Ag nanoparticles with a diameter of 6–8 nm were aligned at the same depth in a delta layer in the bottom region of the SiO2at a distance of 2 nm from the boundary.