波长扩展InGaAs探测器的量子效率优化

通过建立双异质结型InGaAs探测器光响应的理论模型,分别对正面和背面进光时InP基波长扩展In0.8Ga0.2As/In0.79Al0.21As PIN探测器结构参数与光响应特性的关系进行了研究,模拟结果与采用GSMBE方法研制器件的实测数据吻合较好.此外,还提出了两种改良的背照射InGaAs探测器结构,并对其光响应特性进行了模拟计算,还基于模拟结果对器件结构参数进行了优化设计.     

120Gbit/s甚短距离并行光模块的研制

基于12通道垂直腔面发射激光器(VCSEL)阵列和12通道PD探测器阵列,设计制作了120 Gbit/s甚短距离的12通道并行光发送模块和12通道并行光接收模块.基于电磁场、传输线理论的信号完整性设计,减小了通道间串扰;利用过孔模型分析和阻抗设计,解决信号反射问题;且通过减小金丝直连长度等手段增加了通道带宽.光模块单通道传输速率不小于10Gbit/s,12通道并行总传输速率高达120 Gbit/s.并行光模块具有高速率、高集成度以及低成本等特点,为短距离高速率并行光传输系统提供具竞争力的解决方案.     

新型电单负材料结构在天线互耦抑制中的应用

单负材料所具有的电磁禁带特性可应用于阵列天线中降低天线单元间的互耦.文中研究设计了一种电单负材料结构单元ENG-APSL, 采用等效电路和波导传输法分析了ENG-APSL的电磁特性, 并提取等效参数.然后, 将基于ENG-APSL单元构成的隔离器用于抑制微带阵列单元间的互耦.研究表明, 天线阵列单元间距为0.37λ₀(λ₀为天线工作频率波长)条件下, 加载隔离器后天线阵列单元的E面耦合度降低了21 dB, 并且在工作频率(5.1 GHz)附近隔离度大于25 dB的带宽达到5.1%.同时, 该隔离器具有结构简单、尺寸小的突出优势.     

基于肖特基二极管的太赫兹准光探测器设计方法与成像性能研究

设计了一款太赫兹准光探测器, 该探测器主要由砷化镓肖特基二极管芯片以及高阻硅透镜组成.为了减小所设计芯片的欧姆损耗, 将天线图案生长在了半绝缘砷化镓层上.在335～350GHz频率范围内, 准光探测器的实测电压响应率为1360～1650V/W, 双边带变频损耗为10.6～12.5dB.对应估算的等效噪声功率为1.65～2pW/Hz1/2.基于所设计的准光探测器进行了成像实验, 该实验分别在直接检波和外差探测两种模式间进行, 成像结果表明所设计的太赫兹准光探测器能够满足太赫兹成像方面应用.     

InP基及含磷化合物HBT材料的GSMBE生长与特性

通过对外延材料结构设计和GSMBE生长工艺的深入研究,解决了生长InP基及含磷化合物HBT外延材料的关键问题,建立了稳定优化的GSMBE生长工艺,研制出性能优良的φ50mm InP基HBT和φ100mm InGaP/GaAs HBT外延材料.所发展的GSMBE外延技术,在As/P气氛切换、基区p型重掺杂扩散抑制、双异质结HBT结构设计等方面具有自己的特色.器件单位采用所提供的外延材料研制出的InP基HBT和InGaP/GaAs HBT器件与电路,达到了目前采用国产HBT外延材料研制的最好水平.     

InP基及含磷化合物HBT材料的GSMBE生长与特性

通过对外延材料结构设计和GSMBE生长工艺的深入研究,解决了生长InP基及含磷化合物HBT外延材料的关键问题,建立了稳定优化的GSMBE生长工艺,研制出性能优良的φ50mm InP基HBT和φ100mm InGaP/GaAs HBT外延材料.所发展的GSMBE外延技术,在As/P气氛切换、基区p型重掺杂扩散抑制、双异质结HBT结构设计等方面具有自己的特色.器件单位采用所提供的外延材料研制出的InP基HBT和InGaP/GaAs HBT器件与电路,达到了目前采用国产HBT外延材料研制的最好水平.     

高光束质量新型垂直腔面发射激光器阵列

报道了一种具有新型排列方式的垂直腔面发射半导体激光器(VCSEL)阵列.通过调制阵列中各单元直径以及单元间距,得到1 kW/cm2的高功率密度和高斯远场分布,且在工作电流0～6 A内远场发散角均小于20°.阵列山直径分别为200 μm,150 μm和100 μm成中心对称分布的5个单元组成,单元圆心间距分别为250μm和200μm.在室温连续工作条件下.阵列在注入电流4 A时达最大输出功率880 mw,斜率效率为0.3 W/A,具有0.56 A的低阈值电流,微分电阻0.09 Ω.与具有相同出光面积的4×4二维阵列相比,这种新型阵列在出光功率、阈值电流、光谱特性及远场分布等方面均具有优越性.模拟了阵列各单元叠加后的近场远场光强分布,结果表明得到的新型阵列的远场分布与实验结果吻合较好.     

硅PIN光电探测器阵列的串扰分析

在利用高密度线性阵列探测器成像时,探测阵列单元间的串扰将直接影响器件的成像质量.文章对厚度为100μm的背照式PIN光电探测器线性阵列的电串扰特性进行了分析,通过Silvaco TCAD器件仿真软件对阵列的暗电流和光电流进行了仿真,分析了像元间的电串扰特性,同时对比分析了保护环结构对器件的暗电流和电串扰特性的影响.仿真结果表明,保护环结构器件的暗电流和电串扰性能均优于无保护环的结构,在有保护环时PIN器件的串扰是无保护环结构的1/5.     

高性能石墨烯/硅纳米线阵列异质结光探测器

设计了基于石墨烯/硅纳米线阵列异质结的高灵敏度自驱动光探测器。该探测器中的纳米线阵列为直径约为100nm的周期性结构,表面纳米结构的光捕获效应可以有效地抑制入射光的反射,增加了有效光照面积,增强了异质结的吸收,从而提高了器件的光电检测性能。实验制备出的异质结在±3 V偏压下表现出明显的电流整流特性,整流比为693×105。此外,由于纳米线阵列的光捕获效应增强了探测器在紫外到近红外的吸收,所以该探测器的探测范围可以从紫外到近红外光。在入射波长810nm、光强为90 μW/cm2的光照下,光探测器的光电流响应度可以达到056 A·W-1,光电压响应度达124×106 V·W-1,探测率为118×1012Jones。更重要的是,该器件具有30/32 μs的快速升/降响应速度。     

基于逐点扫描的探测器阵列靶标定系统

为分析激光发射系统的性能,需要测量激光光斑的绝对功率密度时空分布,探测器阵列靶是有效手段之一。为实现定量分析,需要对探测器阵列靶进行标定。探测器阵列靶单元数多,标定难度大,设计有效的标定系统十分重要。设计了一种新的标定系统,该系统采用逐点扫描的方式,具有适用性广、成本低、精度高等特点。并以某项目为例对标定系统的测量不确定度进行了测试分析,结果表明:可见光波段的测量不确定度为2.99%,近红外波段的测量不确定度为3.62%,中红外波段的测量不确定度为6.17%.该标定系统是探测器阵列靶标定的有效手段,值得借鉴。     

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.