Epitaxial Films and Nanostructures

外延薄膜和纳米结构

• 批准号: RGPIN-2016-06618
• 负责人: Preston, John
• 金额: $ 2.4万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638287
• 关键词: Epitaxial; Films; Nanostructures

The proposed research program will explore two recent unexpected discoveries associated with two particular examples of oxide substrates being used to support epitaxial structures. The first case involves a gold film evolving into epitaxial gold nanoparticles on a spinel substrate. There is a large surface energy associated with the gold spinel surface. This energy drives the dewetting of the gold at modest temperatures with the gold film breaking up into nanometer scale particles as expected. However, gold and spinel have a near lattice match so that at somewhat higher temperatures the gold nanoparticles rotate such that they are aligned with the underlying substrate. At yet higher temperatures, a self-limited chemical reaction takes place, forming an epitaxial bilayer of gold oxide. There is strong evidence that this bilayer represents an equilibrium complexion i.e. that it provides the lowest free energy interface between the gold and spinel crystalline states. The evidence is that with annealing at higher temperatures or longer times the bilayer does not appear to grow, the adhesion of the gold nanoparticle increases dramatically and that the estimate of the surface tension from the contact angle is greatly reduced. If equilibrium complexions could be introduced or approximated at the interface of insulating layers and metallization layers then the reliability of many semiconductor could be improved.

拟议的研究计划将探索最近的两个意外发现，这些发现与用于支撑外延结构的氧化物衬底的两个特定示例相关。第一种情况是金膜在尖晶石基底上演化成外延金纳米颗粒。金尖晶石表面具有很大的表面能。这种能量驱动金在适度的温度下去湿，金膜如预期分解成纳米级颗粒。然而，金和尖晶石具有接近的晶格匹配，因此在稍高的温度下，金纳米粒子旋转，使得它们与下面的基底对齐。在更高的温度下，会发生自限性化学反应，形成氧化金外延双层。有强有力的证据表明，该双层代表了平衡状态，即它提供了金和尖晶石晶态之间的最低自由能界面。证据是，随着在更高温度或更长时间的退火，双层似乎不再生长，金纳米颗粒的粘附力急剧增加，并且根据接触角估计的表面张力大大降低。 如果可以在绝缘层和金属化层的界面处引入或近似平衡络合物，则可以提高许多半导体的可靠性。