Primitive Mechanisms of Epitaxial Growth of Germanium Silicon Using an Accurate Quantum Mechanical Total Energy Expression

一种新开发的方法，它结合了参数化，量子 硅的机械最近邻总能量表达式 一个“虚构的拉格朗日”分子动力学方案， 由汽车和帕里内洛将扩大到模型锗- 硅固溶体系统 一种新颖的全方位参数化 锗硅系统的总能量表达式， 具有完全可转移性的局域密度近似将 被建造。 这个总能量表达式是参数化的 针对来自实验的大型数据库， 最先进的局部密度近似计算。 在计算上，它只会比 硅单独的计算和有限温度模拟 可以在几十个克雷YMP小时内完成数百个原子， 比最佳局部密度快约50倍 近似计算 薄膜外延生长的研究 锗硅将通过将问题分解为更小的 可以单独研究的成分;即， 表面，台阶和扭结，原子的粘附和扩散， 这个表面，在一个放松的扭结附近的原子的动力学，和生长， 一步一步的走。 %%% 将开发计算技术， 锗硅混合物的能量-一种重要的材料， 电子工业。 这项技术将加速 重要属性的计算。 所提出的技术 有可能对这些国家 性能计算，并可应用于其他材料， 科学和商业利益。

A newly developed method which incorporates a parametrized, quantum mechanical, nearest neighbor total energy expression for silicon into a "ficticious Lagrangian" molecular dynamics scheme developed by Car and Parinello will be expanded to model the germanium- silicon solid solution system. A novel full range, parametrized total energy expression for the germanium-silicon system based on the local density approximation with complete transferability will be constructed. This total energy expression is parameterized against a large data base which is derived from experiment and state of the art local density approximation calculations. Computationally, it will only be slightly more demanding than the calculations for silicon alone, and finite temperature simulations of hundreds of atoms could be performed in tens of Cray YMP hours, a factor of about 50 more rapidly than the best local density approximation calculations. The study of the epitaxial growth of germanium-silicon will be done by breaking the problem into smaller components which can be studied individually; namely, relaxation of surfaces, steps and kinks, sticking and diffusion of an atom on this surface, dynamics of atoms near a relaxed kink, and growth of kinks into steps. %%% Computational techniques will be developed to model the total energies of germanium-silicon mixtures - an important material for the electronics industry. The proposed technique will accelerate the calculation of important properties. The proposed techniques have the potential to have a major impact on the way that these properties are calculated and can be applied to other materials of scientific and commercial interest.