Study of Growth/Etch Front Roughening at Far-From-Equilibrium

在远离平衡的条件下，表面在刻蚀/生长过程中形成的界面粗糙度不能用传统的统计力学来描述。动态标度假说与模拟和连续介质理论相结合的最新发展为非平衡物理研究指明了一个令人振奋的新方向。一些实验系统将被用来定量地探索远离平衡的粗化现象，并被设计来检验动态标度假说。这些系统包括表面刻蚀(等离子体刻蚀、离子溅射和反应离子刻蚀)和表面薄膜(包括聚合物)的生长。将使用最先进的技术在垂直(界面宽度)和水平(横向相关)方向上跨越较大的长度范围，以实时测量界面粗糙度。粗糙度和形貌将使用噪声诱导和其他生长机制来模拟，包括侧壁生长和各向异性生长。由实验和模拟得到的粗糙度指数和界面生长指数将被用来建立动态标度现象的普适类。通过对生长/刻蚀前沿粗糙现象的基本了解，结合实时监测表面的表征技术，可以在实际应用中控制界面粗糙度。界面粗糙度是薄膜和器件加工中的中心问题之一，它直接控制薄膜和器件的许多物理和化学性质。这项研究调查了在远离平衡的条件下表面生长/刻蚀过程中界面粗糙度形成的基本方面。在刻蚀领域，将使用半导体加工技术，如等离子刻蚀、离子溅射和反应离子刻蚀。研究气相沉积生长聚合物薄膜的形态和演化将是生长领域的一项新的努力。学生将利用原子力显微镜、光散射、X射线衍射和电子衍射来测量和量化界面粗糙度。对随时间变化的粗糙度数据将使用具有分维的动态标度理论进行分析。根据这一研究计划培训的学生将平稳过渡到学术或工业环境。*

9971265Wang The formation of interface roughness during the etching/growth of surfaces under far-from-equilibrium conditions cannot be described by conventional statistical mechanics. Recent development of the dynamic scaling hypothesis coupled with simulations and continuum theory point to an exciting and new direction in the area of non-equilibrium physics research. A number of experimental systems will be used to explore quantitatively the roughening phenomena at far-from-equilibrium and are designed to test the dynamic scaling hypothesis. The systems include etching of surfaces (plasma etching, ion sputtering, and reactive ion etching) and growth of films (including polymers) on surfaces. State-of-the-art techniques will be used to span a wide length scale both in the vertical (interface width) and horizontal (lateral correlation) directions to measure the interface roughness in real-time. The roughness and morphology will be simulated using noise-induced and other growth mechanisms including sidewall growth and anisotropy growth. The roughness exponent and interface growth exponent measured from experiments and simulations will be used to establish the universality class of dynamic scaling phenomenon. It is anticipated that a fundamental understanding of the growth/etch front roughening phenomena coupled with characterization techniques to monitor the surface in real-time will allow the control of interface roughness in practical applications.%%%Interface roughness is one of the central issues in thin film and device processing and it directly controls many physical and chemical properties of films and devices. This research investigates fundamental aspects of the formation of interface roughness during growth/etching of surfaces under far-from-equilibrium conditions. In the etching area, semiconductor-processing techniques such as plasma etching, ion sputtering, and reactive ion etching will be used. A new effort in the growth area will be initiated to study the morphology and evolution of polymer film growth by vapor deposition. Students will utilize atomic force microscopy, light scattering, x-ray diffraction and electron diffraction to measure and quantify the interface roughness. The time dependent roughness data will be analyzed using dynamical scaling theories with fractal dimensions. Students trained under this research program will have a smooth transition to either an academic or an industrial environment.***