In-situ Fabrication of Diamond Structures for Microelectromechanical Systems (MEMS) Using a Novel Pulsed Laser Process

虽然集成电路和微机电系统材料微加工的最新进展主要依赖于光刻技术和物理或化学蚀刻的结合，但这些材料去除工艺对于硬涂层（如金刚石）的微加工特征不是很有用。本项目研究了一种新的方法，通过脉冲双激光烧蚀工艺和脉冲CO2激光产生的瞬态热微图像化工艺，原位制造从亚微米到亚毫米尺寸的各种金刚石微结构。将研究在硅衬底上生长独立的金刚石细观结构和所需的金刚石微结构。该工艺将为金刚石提供一种多功能的微加工工具，可以扩展到其他坚硬的摩擦学材料。实验研究包括确定激光烧蚀羽流中能量、激发和电离度之间的关系以及与衬底的相互作用。一个理论模型的动态瞬态激光诱导的热分布在衬底将开发预测可能的特征尺寸基于实验结果。该项目为研究生和本科生提供了获得激光物理、材料科学和热建模经验的机会。

While recent advances in the micro-fabrication of materials for the integrated circuits and microelectromechanical systems primarily rely on combinations of lithographic techniques and physical or chemical etching, these material removal processes are not very useful for the micro-fabrication of features in hard coating such as diamond. This project investigates a novel method for the in-situ fabrication of a large variety of diamond microstructures ranging from the sub-micron to the sub-millimeter dimension by a pulsed dual-laser ablation process with a pulsed CO2 laser generated transient thermal micro-patterning process. The growth of both freestanding diamond meso-structures as well as desired microstructures of diamond on silicon substrates will be studied. The process will provide a versatile microfabrication tool for diamond that may be extended to other hard, tribological materials. The experimental study includes the determination of the relationship between energy, excitation and degree of ionization in the laser-ablated plume and the interaction with the substrate. A theoretical model of the dynamics of the transient laser-induced thermal profiles on the substrate will be developed to predict possible feature sizes based upon the experimental findings. The project provides exciting opportunities for graduate and undergraduate students to gain experience in laser physics, materials science and thermal modeling.