微型卫星的微电子机—电系统集成技术

未来科研卫星的质量，功耗和体积均要大大减少，这一需求促使NASA致力于微电子机－电系统（MEMS）这一新技术的开发。MEMS除重量轻，结构紧凑，功耗小这些优点外，它还有许多适合于空间应用的优势，最主要的是MEMS采用高可靠性的固态集成器件，因此其鲁棒性好，适应能力强，此外，将多个相同的MEMS装置组成阵列便于构成超大规模集成的分布式容错结构。这些芯片级的微电子机－电系统在过去10年中已进入研究阶段，最近在汽车和生物医学传感器等地面应用领域已转入商用开发阶段。尽管MEMS技术在空间应用领域前途远大，但目前尚未达到其成熟阶段，要使MEMS装置走出实验进入空间环境实际应用，还需进行大量的工作，虽然空间应用可依靠其它工业部门所取得的技术进步作为杠杆，然而要使这些MEMS装置达到上天的水平，还要做大量的技术突破工作。这些技术突破主要是针对空间性能，可靠性和运行性能以及空间结构和飞行鉴定方法等方面。本文旨在明确能使MEMS真正武装空间的这些技术难题，文中还介绍了JPL为突破这些关键技术而进行的研究和开发工作。

A Solenoid-Type Inductor Fabricated by MEMS Technique

A solenoid-type inductor for high frequency application is realized using a micro-electro-mechanical systems (MEMS) technique.In order to achieve a high inductance value and Q-factor,UV-LIGA,dry etching technique,fine polishing and electroplating technique are adopted.The dimensions of the inductor are 1500μm×900μm×70μm,having 41 turns with a coil width of 20μm separated by 20μm spaces and a high aspect ratio of 3.5∶1.The maximum measured inductance of the inductor is 6.17nH with a Q-factor of about 6.

Applying Double Electric Fields to Avoid Deteriorating Movable Sensitive Parts in MEMS During Anodic Bonding

Anodic bonding between silicon and glass with dou bl e electric fields is presented.By this means,the damage caused by the electric f ield to the movable part during bonding can be avoided and the experiment result s show that.

Modeling and Analysis of Electrostatically Actuated MEMS under Combined Nonlinearities, Lorentz Force, and Mechanical Shock

This paper shows an analysis ofMEM S （micro electro mechanical systems） due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam and stationary plate, the pull-in instability happens.

MEMS biomedical implants

The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such as accelerometers and gyros,for handheld electronics application.In parallel,MEMS has also advanced into micro total analysis system(TAS) and/or lab-on-a-chip applications.This article would discuss a relatively new but promising future direction towards MEMS biomedical implants.Specifically,Parylene C has been explored to be used as a good MEMS implant material and will be discussed in detail.Demonstrated implant devices,such as retinal and spinal cord implants,are presented in this article.

Stress control of silicon nitride films deposited by plasma enhanced chemical vapor deposition

Stress controllable silicon nitride(Si Nx) films deposited by plasma enhanced chemical vapor deposition(PECVD) are reported. Low stress Si Nx films were deposited in both high frequency(HF) mode and dual frequency(HF/LF) mode. By optimizing process parameters, stress free(-0.27 MPa) Si Nx films were obtained with the deposition rate of 45.5 nm/min and the refractive index of 2.06. Furthermore, at HF/LF mode, the stress is significantly influenced by LF ratio and LF power, and can be controlled to be 10 MPa with the LF ratio of 17% and LF power of 150 W. However, LF power has a little effect on the deposition rate due to the interaction between HF power and LF power. The deposited Si Nx films have good mechanical and optical properties, low deposition temperature and controllable stress, and can be widely used in integrated circuit(IC), micro-electro-mechanical systems(MEMS) and bio-MEMS.