Theory of Semiconductor Surface Chemistry

特拉华大学的道格拉斯·多伦得到了理论和计算化学项目的资助，继续他对半导体表面化学的理论研究。多伦正在研究有机分子在清洁的(100)硅表面上的周环反应。他正在研究激发表面电子态在这些反应中的作用，以及掺杂剂和合金原子对成键和反应活性的影响。所使用的方法主要是密度泛函理论，表面模型既包括有限团簇，也包括周期性平板。将对Diels-Alder反应进行较详细的研究，目的是了解决定产品选择性的因素，并拓宽可用于该反应的试剂类别。还将研究一类新的周环反应--Si(100)上的1-3偶极加成反应。这项工作将探索这些反应的热力学和动力学，并表征光谱性质，以便与实验进行比较。包括Ge、B和P在内的硅表面掺杂将被用来研究这些原子对结合能、表面电子态和激活能的影响。半导体表面化学是处理渗透到现代生活中的电子器件的基础。随着器件特征达到纳米级，在原子级上控制器件结构的需求变得至关重要。允许对宏观区域进行受控表面修饰的化学处理方法对于允许持续、经济地减小器件尺寸至关重要。无论是实际问题还是根本问题，都使半导体表面化学成为一个活跃且迅速发展的领域。多伦的研究侧重于硅(100)表面反应的理论研究，硅是目前集成电路生产中使用的主要表面。

Douglas Doren of the University of Delaware is supported by a grant from the Theoretical and Computational Chemistry Program to continue his theoretical studies of semiconductor surface chemistry. Doren is studying pericyclic reactions of organic molecules at the clean (100) surface of silicon. He is studying the role of excited surface electronic states in these reactions, and the effect of dopant and alloy atoms on bonding and reactivity. The method being used is primarily density functional theory, and the surface models include both finite clusters and periodic slabs. The Diels-Alder reaction will be studied in some detail with the goal of understanding the factors that determine product selectivity and to broaden the class of reagents that can be used in the reaction. A new class of pericyclic reactions, the 1-3 dipolar additions on Si(100), will also be studied. This work will explore the thermodynamics and kinetics of these reactions, and characterize spectral properties for comparison with experiment. Dopants including Ge, B and P on Si surfaces will be used to study the effects of these atoms on binding energies, surface electronic states and activation energies.Semiconductor surface chemistry is fundamental to processing the electronic devices that pervade modern life. As device features reach the nanometer scale, the need for control over device structure at the atomic level is becoming critical. Chemical processing methods that allow controlled surface modification over macroscopic areas are essential to allow continued, economical reductions in device dimensions. Both practical and fundamental issues have made semiconductor surface chemistry an active and rapidly growing field. Doren's research focuses on theoretical studies of reactions on the (100) surface of silicon, the main surface used currently in integrated circuit production.