射频微机械CPW开关的研究

本文采用聚酰亚胺牺牲层技术和二氧化硅介质隔离技术,成功地在绝缘多晶硅衬底上研制出一种射频微机械CPW开关.初步测试结果如下:开态电容为0.21pF,关态电容为6.1pF,致动电压为22V,关态下的隔离度为35dB,开态下插入损耗为3dB.该工艺完全与硅基IC工艺兼容,这为射频微机械CPW开关与IC实现单片集成化,降低体积提高可靠性打下了基础.     

双膜桥微波MEMS开关

介绍了一种双膜桥微波MEMS开关，给出了开关的设计与优化方法，建立了开关的仿真模型，使用硅表面微机械工艺制造了双膜桥开关样品，其主要结构为硅衬底上制作CPW金属传输线电极和介质层，然后制作具有微电感结构的金属膜桥，提高了开关隔离度。利用HFSS软件仿真的结果表明，该开关在微波低频段(3～6GHz)有着很好的隔离性能。研制的开关样品在片测试的电性能指标为：插损小于0．3dB，隔离度大于40dB，驱动电压小于24V。     

双膜桥微波MEMS开关

介绍了一种双膜桥微波MEMS开关,给出了开关的设计与优化方法,建立了开关的仿真模型,使用硅表面微机械工艺制造了双膜桥开关样品,其主要结构为硅衬底上制作CPW金属传输线电极和介质层,然后制作具有微电感结构的金属膜桥,提高了开关隔离度.利用HFSS软件仿真的结果表明,该开关在微波低频段(3～6GHz)有着很好的隔离性能.研制的开关样品在片测试的电性能指标为:插损小于0.3dB,隔离度大于40dB,驱动电压小于24V.     

双膜桥微波MEMS开关

介绍了一种双膜桥微波MEMS开关 ,给出了开关的设计与优化方法 ,建立了开关的仿真模型 ,使用硅表面微机械工艺制造了双膜桥开关样品 ,其主要结构为硅衬底上制作CPW金属传输线电极和介质层 ,然后制作具有微电感结构的金属膜桥 ,提高了开关隔离度。利用HFSS软件仿真的结果表明 ,该开关在微波低频段 (3～ 6GHz)有着很好的隔离性能。研制的开关样品在片测试的电性能指标为 :插损小于 0 .3dB ,隔离度大于 4 0dB ,驱动电压小于 2 4V。     

微机械微波/射频开关的制备和功能测量研究

讨论了微机械微波/射频开关的原理、制备工艺和功能测试.微机械接触式微波/射频开关的基本结构是微波共平面波导,在制备工艺中首先考虑的是工艺兼容性,为此选择以PECVD生长的氮化硅为悬臂梁,聚酰亚胺为牺牲层.功能测试表明,该工艺制备的微机械开关的执行电压只有25V,优于同类微机械开关的指标,同时它具有良好的响应特性.     

基于砷化镓衬底的RF MEMS膜开关

射频微机械开关由于其优越的高频特性在微波和毫米波电路中表现出巨大的应用前景。但是目前的微机械开关都是制作在硅基衬底上的，难于与后面的高频砷化镓处理电路相集成。本文介绍了基于砷化镓衬底的RFMEMS膜开关，着重介绍了开关的工作原理、制作过程和测试结果。     

基于砷化镓衬底的RF MEMS膜开关

在低损耗的微波和毫米波电路中 ,静电驱动的射频微机械 (MEMS)开关表现出巨大的应用前景。和传统的半导体开关相比 ,由于在结构上消除了金属 -半导体结和 PN结 ,MEMS开关具有极其优越的高频特性 ,例如 MEMS开关具有极低的插入损耗和较高的隔离度。简单的来说 ,射频微机械开关是由静电驱动的金属梁和射频信号线构成。自从 1 979年 Petersen首次研制出金属包覆的静电悬臂梁开关以来 ,多种结构形式的 MEMS开关被用于控制微波信号 ,例如悬臂梁结构、旋转传输线结构和膜结构等。到目前为止 ,研究的射频微机械开关主要有两种结构形式 :金…     

基于砷化镓衬底的RF MEMS膜开关

射频微机械开关由于其优越的高频特性在微波和毫米波电路中表现出巨大的应用前景。但是目前的微机械开关都是制作在硅基衬底上的 ,难于与后面的高频砷化镓处理电路相集成。本文介绍了基于砷化镓衬底的RFMEMS膜开关 ,着重介绍了开关的工作原理、制作过程和测试结果     

一种用于隔离放大器的微机械开关

介绍了一种新型的隔离放大电路,采用微机械开关实现“飞电容”结构。这种隔离放大电路具有许多优点:电路结构简单、尺寸小、成本低、隔离电压高、电磁兼容性能优良,很容易组成多通道隔离电路等;在30V驱动电压下测试,微机械开关的延时小于50μs,隔离电压大于110V。对设计、制造出的微机械开关隔离放大器进行了测试,证明该电路的精度优于2%。     

基于砷化镓衬底的RF MEMS膜开关

射频微机械开关由于其优越的高频特性在微波和毫米波电路中表现出巨大的应用前景.但是目前的微机械开关都是制作在硅基衬底上的,难于与后面的高频砷化镓处理电路相集成.本文介绍了基于砷化镓衬底的RF MEMS膜开关,着重介绍了开关的工作原理、制作过程和测试结果.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.