Reliability of MEMS Materials and Components

本研究的目的是对选定的微电机、微开关和微齿轮系统的配合部件表面进行详细的性能分析和微摩擦学研究，研究其与设备运行时间的关系，从而确定微设备和部件在运行过程中失效的相关机制。长期以来，人们一直怀疑MEMS器件的失效是由于器件配合表面摩擦学性能的急剧变化或退化而发生的。将使用AFM/FFM研究设备操作对与配合表面相关的重要摩擦学参数（如表面粗糙度、微尺度摩擦、粘性和机械完整性）的影响。将开发不同半径的尖端来模拟不同尺寸的粗糙接触，以研究配合表面的粘附和摩擦。通过使用纳米开尔文探针来检测磨损的前兆，将研究磨损前表面结构的变化，以确定与配合表面降解相关的机制。研究启动电流等器件参数的测量。对指示器件失效的停止电流等进行测量，并与不同工况下的摩擦学参数进行比较。这将有助于了解摩擦学参数对器件失效的影响。该研究的另一个目标是确定用于MEMS器件的新材料，润滑剂和超薄涂层。目前使用的材料-硅和多晶硅薄膜将与新的候选材料如SiC薄膜和其他陶瓷薄膜进行比较。这里的目的是寻找具有最小摩擦/粘滞和优异磨损性能的材料。研究厚度从10纳米到3.5纳米甚至更小的超薄硬质非晶碳涂层，以确定具有最佳划伤/耐磨性的最薄涂层。通过对各种潜在材料制成的MEMS元件进行研究，研究其工程性能并评估其可靠性。微型马达和其他MEMS装置将从研究合作者那里获得，他们将制造这些装置。通过这项研究，将更好地估计MEMS器件的可靠性，并将大大促进对这些器件失效机制的理解。还将确定适合MEMS器件的新材料，涂料和润滑剂。因此，这项研究将对MEMS技术和微摩擦学科学领域都有好处

9820022BhushanThe objective of the proposed research is to conduct a detailed performance analysis and microtribological study of the mating component surfaces in selected micromotors, microswitches and microgear systems as a function of operating time of the devices, thereby identifying the mechanisms associated with microdevice and component failure during operation. It has been long suspected that failure of MEMS devices occurs due to a drastic change or degradation of tribological properties of the mating surfaces in the device. The effect of device operation on the important tribological parameters associated with mating surfaces such as surface roughness, microscale friction, stiction and mechanical integrity will be studied using an AFM/FFM. Tips of different radii to simulate asperity contacts of different sizes will be developed to study the adhesion and friction of mating surfaces. By using a Nanoscale Kelvin Probe to detect precursors of wear, changes in the structure of the surfaces prior to wear will be studied in order to identify mechanisms associated with degradation of the mating surfaces. Studies to measure device parameters such as start-up current. stopping current etc., which are indicative of device failure, will be conducted and these will be compared with tribological parameters under different operating conditions. This will help to understand the effect of tribological parameters on device failure. Another objective of the study is to identify new materials, lubricants and ultra-thin coatings for use in MEMS devices. Coupons of currently used materials - silicon and polysilicon films will be compared to new candidate materials such as SiC films and other ceramic films. The aim here is to look for materials that exhibit minimum friction/stiction and superior wear performance. Ultra-thin hard amorphous carbon coatings of thicknesses ranging from 10 nm down to 3.5 nm and less will be studied in order to identify the thinnest coatings with the best scratch/wear resistance. By conducting studies on MEMS components made from various potential materials anti coatings, their engineering performance will be studied and their reliability evaluated.The micromotors and other MEMS device will be obtained from research collaborators who will fabricate the devices. Through this study, reliability of the MEMS devices will be better estimated and understanding of failure mechanisms in these devices will be significantly advanced. New materials, coatings and lubricants that are well suited for MEMS devices will also be identified. This study will therefore be of mutual benefit to the fields of both MEMS technology and microtribology science.***