Growth Dynamics of Thin Metal Films on Compound Semiconductor Surfaces

对化合物半导体表面金属覆盖层形成的基本理解将为各种复杂的金属界面现象提供有价值的见解，这些现象对电子设备的智能设计至关重要。这项工作将集中于开发与化合物半导体表面金属薄膜有序结构的形成和发展相关的动力学过程的定量模型。初期的工作将集中在V族和金属在III-V族化合物半导体表面的吸附上。在研究的第一阶段，将新开发的时间依赖蒙特卡罗模型与紧结合模型和第一性原理赝势总能量模型相结合，研究砷化镓上锑和铋在亚单层到单层状态下的生长。对化学吸附、迁移、结合和脱附等基本化学过程的描述将有助于对基本表面反应的全面理解。在研究的第二阶段，将研究锑和铋在2 - 20单层范围内的生长，其中控制伪晶生长和向三维岛生长过渡的因素发生。未来的工作将解决薄膜缺陷形成的问题，例如沉积过程中二维岛屿生长的性质，以及确定缺陷形成的重要条件。该基金支持一名博士后，并与巴特尔太平洋西北实验室的研究人员合作完成。

A fundamental understanding of the formation of metal overlayers on compound semiconductor surfaces will provide valuable insight into a variety of complex metal-interfacial phenomena crucial to the intelligent design of electronic devices. This work will focus on developing a quantitative model of the kinetic processes associated with the formation and development of ordered structures for metallic films on compound semiconductor surfaces. Initial efforts will focus on the adsorption of group V and metals on the surface of III-V compound semiconductors. %%% In the first phase of the research, a newly developed time- dependent Monte Carlo model will be combined with tight-binding and first-principles pseudopotential total energy models to investigate the growth of antimony and bismuth on gallium arsenide in the sub- monolayer to one monolayer regime. The desciption of fundamental chemical processes such as chemisorption, migration, incorporation, and desorption, will contribute to a comprehensive understanding of the elementary surface reactions. In the second phase of the research the growth of antimony and bismuth in the range of two - twenty monolayers will be examined where factors controlling pseudomorphic growth and the transition to three-dimensional island growth take place. Future work will address the issue of film defect formation, such as the nature of two-dimensional island growth during deposition, and identification of the conditions important for defect formation. The grant supports a postdoctoral associate and is done in collaboration with researchers at Battelle Pacific Northwest Laboratories.