Selective Chemical Liquid Deposition Process for Mini-Structures and Microsystems

这个为期一年的项目的目标是证明一种新的选择性化学液体沉积工艺(SCLD)的可行性，该工艺创建的三维结构具有比其他沉积和固体自由形式制造工艺更好的性能和更低的制造残余应力。目前，用于制造微结构和MEMS的技术大多涉及复杂而昂贵的工艺，如光刻、硅表面加工和硅体加工。例如，化学气相沉积工艺是一种中到高温的沉积工艺，它会在所生产的薄膜中引入缺陷和残余应力。为了克服化学气相沉积的缺点，探索化学沉积在微型结构和微系统制造中的新应用和新材料，SCLD工艺将在一个自动化过程中集成化学液体沉积研究、固体自由形式制造、系统和控制以及微型结构和微系统(MSMS)。开发SCLDP-MSMS的研究计划研究室温溶液或液体反应物从喷嘴喷出时的受控沉积，与热的衬底接触，导致蒸发、分解或反应。预计反应后的固体产物将沉积在衬底上，通过控制喷嘴的运动和喷涂时间，可以通过逐层扫描技术形成所需的三维微结构。在SCLDP-MSMS系统的概念设计、材料选择和测试方面进行了初步工作。结果令人振奋。为了将这一新概念变为现实，将开展以下工作：(1)对化学液体沉积过程进行广泛的材料研究和测试，以寻找更多可用于沉积金属、陶瓷、硅、复合材料和碳结构的化学品；(2)设计和制造SCLDP-MSMS原型机器，并使用该原型机器制造微结构；以及(3)对SCLDP进行额外的实验，为工艺建模和计算机模拟提供必要的数据、边界条件和分析信息。

The objective of this one year project is to demonstrate the feasibility of a novel Selective Chemical Liquid Deposition process (SCLD) that creates 3-D structures with better properties and lower fabrication-induced residual stresses than other deposition and solid freeform fabrication processes. Currently most of the technologies used in fabrication of microstructures and MEMS involve sophisticated and expensive processes, such as photo-lithography, silicon surface machining, and silicon bulk machining. For example, chemical vapor deposition processing is a moderate to high temperature deposition process that introduces defects and residual stresses into the films produced. To overcome CVD shortcomings and to explore new chemical deposition applications and new materials in the fabrication of mini-structures and microsystems, the SCLD Process will integrate chemical liquid deposition research, solid freeform fabrication, systems and control, and mini-structures and microsystems (MSMS) in one automated process. The research plan for developing SCLDP-MSMS investigates the controlled deposition as a room temperature solution or liquid reactant is sprayed from a nozzle, making contact with a hot substrate, resulting in evaporation, decomposition, or reaction. It is expected that the reacted solid products will deposit on the substrate and that by controlling the motion of the nozzle and the spray time, a desired 3-D microstructure can be formed through a layer-by-layer scanning technique.Preliminary work has been done on the conceptual design of the SCLDP-MSMS system, materials selection, and testing. The results are promising. In order to turn this new concept into a reality, the following tasks will be carried out: (1) conduct extensive materials research and testing on the chemical liquid deposition process to find more chemicals which can be used to deposit metals, ceramics, silicon, composite, and carbon structures; (2) design and build a prototype SCLDP-MSMS machine and use the prototype machine to make microstructures; and (3) perform additional experiments on the SCLDP to provide necessary data, boundary conditions and analysis information for process modeling and computer simulation.