SBIR Phase I: Investigation of Charge Trapping in Plasma Enhanced Chemical Vapor Deposition (PECVD) Dielectrics Using Electrostatically Actuated Mechanical Resonators

这个小型企业创新研究(SBIR)第一阶段项目将开发一种测量介质中电荷陷阱的新方法。通过将其应用于等离子体增强化学气相沉积(PECVD)、氮化物和氧化物的表征，证明了该方法的可行性。这些材料的沉积化学留下了陷阱位置，当受到强大的电场时，这些陷阱位置捕获电荷。陷阱电荷影响使用这些介质的微电子机械(MEM)器件的稳定性和性能。提出了一种利用谐振、静电驱动的机械结构来测量悬浮介质层中电荷的新技术。使用网络分析仪测量的设备阻抗的实际部分可以与捕获电荷引起的介质中电场的变化相关联。PECVD电介质是MEM设备(光学部件、射频部件和医疗成像部件)的关键组成部分，实现了35亿美元的年销售额。虽然该技术本身不是商业产品，但它广泛适用于使用悬浮PECVD介质层的MEMS器件的工程，如射频(RF)开关和微镜。这种对高度工艺敏感的PECVD电介质中电荷捕获的控制将使我们能够实现我们的超声设备在医学成像应用中的全部商业潜力。

This Small Business Innovation Research (SBIR)Phase I project will develop a novel way to measure charge trapping in dielectrics. The feasibility of our method by applying it to the characterization of plasma enhanced chemical vapor deposition (PECVD) nitride and oxide will be demonstrated. The deposition chemistry of these materials leaves trap sites that capture charge when subjected to large electric fields. Trapped charge affects the stability and performance of micro-electro-mechanical (MEM) devices that employ these dielectrics. A novel technique that uses a resonant, electro-statically actuated mechanical structure to measure charge trapped in a suspended dielectric layer is proposed. The real part of the device impedance, measured using a network analyzer, can be correlated to changes in electric field in the dielectric resulting from trapped charge..PECVD dielectrics are critical constituents in MEM devices that enable $3.5 Billion in annualized sales (optical components, RF components, and medical imaging components). Although the technique itself is not a commercial product, it is broadly applicable to the engineering of MEMs devices utilizing suspended PECVD dielectric layers, such as radio frequency (RF) switches and micro-mirrors. This control of charge trapping in highly process sensitive PECVD dielectrics will allow us to realize the full commercial potential of our ultrasound devices in medical imaging applications.