毫米波RF-MEMS单片集成0/π移相器

介绍了一种毫米波RF-MEMS单片集成反射型0/Π移相器的设计、制造和测试.实测性能与设计结果吻合较好,达到的电性能指标为:在35GHz-38GHz频率范围内,电压驻波比小于1.8,参考态插入损耗为3.5±1.0dB,相移态插入损耗为2.0±0.6dB,相移为180°±6°.芯片尺寸:2.6mm×2.1mm×0.2mm.满足了插损低并具有电路拓扑的要求.     

Ku波段6bit数字衰减器MMIC的小型化设计

基于0.25μm GaAs增强/耗尽(E/D)型赝配高电子迁移率晶体管(PHEMT)工艺,设计并实现了一款集成了6 bit并行驱动器的数字衰减器单片微波集成电路(MMIC)。该衰减器采用T型衰减网络结构,不仅缩小了芯片面积,并且可实现较好的衰减精度和衰减附加相移。芯片在片测试结果表明,在-5 V电源电压下驱动器的静态电流为1.8 mA,响应速度为25 ns。在9~18 GHz频率范围内,衰减器芯片的插入损耗不大于3.6 dB,均方根衰减精度不大于0.7 dB,衰减附加相移为-2°~4°,输入电压驻波比(VSWR)不大于1.25∶1,输出VSWR不大于1.5∶1。芯片尺寸为1.6 mm×0.6 mm×0.1 mm。该电路具有响应速度快、功耗低、面积小、衰减附加相移小等优点,可广泛应用于通信设备和微波测量系统中。     

一款高精度大衰减量单片数控衰减器

介绍了一款高精度大衰减量单片数控衰减器的主要技术指标和设计方法。电路设计基于Agilent ADS微波软件设计环境,采用GaAs HFET工艺技术实现。对开关器件建模流程和数控衰减器电路设计流程分别作了相应的描述。针对不同衰减值的基本衰减位,选择合适的衰减拓扑。通过采用创新的大衰减量衰减结构,既实现了63.5 dB的大衰减量,又满足其衰减精度的要求,还达到了整个单片数控衰减器低插入损耗和高衰减精度的目标。单片电路测试结果为:在3～100 MHz工作频率范围内,插入损耗≤2.2 dB,驻波比≤1.4∶1,衰减范围为0.5～63.5 dB。测试结果表明设计方法有效、可行。电路尺寸为3.5 mm×1.4 mm×0.1 mm,控制电压为0 V和-5 V。     

高性能2 ~ 18GHz 超宽带MMIC 6 位数字衰减器

介绍了一种高性能2～18GHz MMIC 6位GaAs PHEMT数字衰减器的设计、制造和测试结果。研制的单片数字衰减器衰减步进为0.5dB;最大衰减范围为31.5dB;参考态插入损耗<5.71dB;所有衰减态的输入、输出电压驻波比<1.8;衰减精度:+2.31dB/-0.51dB;插入相移:+6.28°/-1.53°;64态幅度均方根误差<1.0dB;64态相移均方根误差<1.3°;芯片尺寸:2.89mm×1.22mm×0.1mm。工艺成品率高达85%。     

一种新颖的4bit和5bit超宽带GaAs单片数字衰减器

介绍了一种新颖的DC～20GHz的4bit和5bit GaAs单片数字衰减器的设计、制造和测试结果.该衰减器的设计采用纵向思维的方法.最终得到的4bit数字衰减器的主要性能指标是:在DC～20GHz频带内,插入损耗≤3.5dB,最大衰减量15dB,衰减步进1dB,衰减平坦度≤0.2dB,衰减精度≤±0.3dB,两端口所有态的电压驻波比≤1.6,相对于参考态,衰减态的插入相移在-10°～5°以内,芯片尺寸1.8mm×1.6mm×0.1mm.5bit数字衰减器的主要性能指标是:在DC～20GHz频带内,插入损耗≤3.8dB,最大衰减量15.5dB,衰减步进0.5dB,衰减平坦度≤0.3dB,衰减精度≤±0.4dB,两端口所有衰减态的电压驻波比≤1.8,相对于参考态,衰减态的插入相移在-14°～2°以内,芯片尺寸2.0mm×1.6mm×0.1mm.     

带数字驱动的Ku波段6bit数控衰减器设计北大核心CSCD

采用GaAs增强/耗尽型（E/D）赝配高电子迁移率晶体管（PHEMT）工艺研制了一款带数字驱动的Ku波段6bit数控衰减器微波单片集成电路（MMIC）。该MMIC将数字驱动和6bit数控衰减器集成在一起,数字驱动电路采用的是直接耦合场效应晶体管逻辑（DCFL）电路,6bit数控衰减器由6个衰减基本态级联组成。版图经过合理优化后,最终的MMIC芯片尺寸为2.4mm×1.3mm。测试结果表明,在12~18GHz,芯片可以实现最大衰减量为31.5dB,步进为0.5dB的衰减量控制。衰减64态均方根误差小于0.6dB,附加相移-2°~2.5°,插入损耗小于6.1dB,输入输出驻波比均小于1.5∶1。     

2～6GHz单片功率放大器

报道了有耗匹配宽带单片功率放大器的研究方法和结果。该两级单片功放电路采用自建的 Root非线性模型进行了谐波平衡分析。在 2 .0～ 6.7GHz频带上线性增益为 17d B,平坦度为± 0 .75d B,输入和输出驻波分别小于 2。全频带上 ,饱和输出功率为 1～ 1.4 W,功率附加效率大于2 0 %。该宽带单片功率放大器在 76mm Ga As单片 MMIC工艺线上用全离子注入、0 .5μm栅长工艺研制完成 ,电路芯片面积为 0 .1mm× 2 .6mm× 2 .7mm。     

一种具有片上译码/放大功能的微阵列电路及其与生物纳米系统的集成

提出了一种用SMIC 0.18μm CMOS混合信号工艺实现的全集成CMOS微阵列生物芯片,并成功地实现了其与一种新的生物纳米系统的集成.该电路实现了19μm×19μm电极的4×4(16单元)阵列,反相电极.电流模式放大器,译码电路,以及逻辑控制电路的单片集成,并能够提供-1.6～1.6V的组装电压,8bit的电位分辨率及39.8dB的电流增益,电源电压为1.8V,而失调和噪声电流分别为5.9nA和25.3pArms.在实验中,利用该电路实现了对30nm聚乙烯醇包裹的磁性粒子的片上选择性组装,并对实验结果进行了讨论,从而验证了该电路的正确性和该集成方法的可行性.     

基于GaN HEMT的S波段小型化内匹配功率管设计

采用总栅宽36 mm的0.5 um工艺GaN HEMT功率管芯,通过合理选择目标阻抗、优化匹配网络,设计了一款包含扼流电路的S波段小型化内匹配功率管.在+48 V、-3.1 V工作电压下,2.7～3.4 GHz内,功率管输出功率≥250 W,功率增益≥12 dB,功率附加效率≥60％,尺寸仅为15 mm×6.6 mm×...     

L波段GaN大功率高效率准单片功率放大器

研制了一款基于NEDI 0.25μm GaN功率MMIC工艺的L波段大功率高效率准单片功率放大器。采用两级拓扑结构,以准单片形式实现。输入采用有耗匹配网络提高芯片的稳定性,级间和末级匹配均采用无耗纯电抗网络,其中末级匹配电路通过低损耗陶瓷电路实现。合理规划前级与末级间推动比,降低前级漏电流,减小末级匹配损耗,优化谐波匹配,实现大功率高效率设计。芯片在28V脉冲电压下工作,在1.2~1.4GHz范围内,实测输出功率大于49dBm,功率增益大于25dB,功率附加效率达到73%。管芯部分及输入匹配电路采用GaN功率MMIC工艺制作,输出匹配电路采用低损耗陶瓷片介质加工,两块电路键合一起总面积8.0mm×5.6mm。     

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.