SBIR Phase I: A Universal Wafer-Level Capping Process for MEMS and Microdevices

这个小型企业创新研究（SBIR）第一阶段项目为微机电系统（MEMS）和其他微型器件提供了一种通用的封盖技术。该技术将允许数千个移动的MEMS设备在惰性气体或真空中免受环境影响。盖晶圆技术本身已经开发-该项目的重点是开发广泛的焊料合金键合技术，这将允许强有力的债券，良好的电气连接到设备和真空/气密密封几乎为零泄漏率的广泛的过程和设备功能。键合强度将取决于金属沉积条件、键合前后的热预算以及每种材料（金-铟、镍-锡、银-铟、银-锡、铜-铟等）之间的化学反应。电特性将涉及优化沉积的金属叠层，以实现低电阻、欧姆接触的优化化学势和低寄生电阻。最初，将通过检查来表征粘合均匀性，但最终将使用密封/真空密封传感器来表征，从而允许精细的泄漏率测量（10-15立方厘米/秒）和放气的表征（原子从微腔表面的解吸），为了表征功能性气密/真空封装的产量。更广泛的影响/该项目的商业潜力是为微机电系统（MEMS）提供通用封装技术。封装（提供电气连接和环境保护）通常是将MEMS推向市场最困难的部分。MEMS市场预计将从2008年的80亿美元增长到2012年的150亿美元。该市场中约有110亿美元的部分可以从具有成本效益的晶圆级封装中受益。众多工业和学术研究人员正在为新兴的MEMS市场开发封装解决方案，包括射频（RF）开关、微流体、微电池、红外（IR）传感器和生物医学设备。该项目中的技术将为所有这些设备提供通用的封装解决方案。这将对市场产生几个影响：1）它将允许这些新兴的MEMS器件进行成本有效的封装，帮助它们进入市场，2）它将简化生产的价值链，允许MEMS设计人员选择最佳工艺/制造公司，而无需考虑其封盖技术，以及3）它将通过允许研究人员专注于MEMS器件本身的功能而不必考虑封装设计来增强创新。

This Small Business Innovation Research (SBIR) Phase I project provides a universal capping technology for microelectromechanical systems (MEMS) and other microdevices. The technology will allow for thousands of moving MEMS devices to get protected from the environment in an inert gas or vacuum. The cap wafer technology itself has already been developed-the focus of this project is to develop a wide range of solder alloy bonding technologies which will allow for strong bonds, good electrical connectivity to the devices and vacuum/hermetic seals with virtually zero leak rates for a wide range of processes and device functionalities. The bond strengths will depend on the metal deposition conditions, the thermal budget before and after bonding and chemical reactions between each material (gold-indium, nickel-tin, silver-indium, silver-tin, copper-indium, etc.). Electrical characterization will involve optimizing the deposited metal stack in order to achieve low electrical resistances, optimized chemical potentials for ohmic contact and low paracitics. Initially the bond uniformity will be characterized by inspection, but will eventually be characterized with hermetically/vacuum sealed sensors allowing for fine leak rate measurement (10-15 cubic centimeters/second) and the characterization of outgassing (desorption of atoms from the microcavity surfaces), in order to characterizing the yield of functional hermetic/vacuum packages.The broader impact/commercial potential of this project is to provide a universal packaging technology for microelectromechanical systems (MEMS). Packaging (providing electrical connectivity and environmental protection) is generally the most difficult part of bringing MEMS to market. The MEMS market is expected to grow from $8 billion in 2008 to $15 billion by 2012. An approximately $11 billion portion of this market can benefit from cost efficient wafer-level packaging. A wide range of industrial and academic researchers are developing packaging solutions for emerging MEMS markets including radio frequency (RF) switches, microfluidics, micro-batteries, infrared (IR) sensors and biomedical devices. The technology in this project will provide a universal packaging solution for all of these devices. This will have several effects on the market: 1) It will allow for these emerging MEMS devices to be cost effectively packaged helping them get to market, 2) it will simplify the value chain for production allowing MEMS designers to choose the optimal process/manufacturing house without consideration of their capping technology and 3) it will enhance innovation by allowing researchers to focus on the functionality of the MEMS device itself without having to consider the package design.