一个用于GSM的80dB动态范围∑-Δ调制器

设计了一个用于GSM系统的Sigma-Delta调制器．GSM系统要求信号带宽大于200kHz，动态范围大于80dB．为了能取得较低的过采样率以降低功耗，采用了级联结构（MASH）来实现，与单环高阶结构相比，它具有稳定及易于实现的优点．设计工作时钟为16MHz，过采样率为32，基带带宽为250kHz，电路仿真可以达到最高82dB的SNDR和87dB的动态范围．芯片采用SMIC0．18μm工艺进行流片，面积为1．2mm×1．8mm．芯片测试效果最高SNDR=74．4dB，动态范围超过80dB，测试结果与电路仿真结果相近，达到了预定的设计目标．芯片工作在1．8V电源电压下，功耗为16．7mW．     

一种并行解扰电路的VLSI实现

解扰电路是数字电视解扰系统的核心部分。着重介绍了实现并行解扰的电路原理图，从VLSI实现的角度来设计电路结构，给出仿真结果，采用0．35μm工艺实现。并行解扰电路集成在解调芯片中，在系统时钟28．8MHz控制下，正常工作，满足数字电视高速数据传输的要求。     

一种低功耗高精度模数转换器的设计

本文描述一个基于0．25μm CMOS工艺的、低功耗的13b，15MS／s流水线ADC的设计。为了达到13b的转换精度，在电路设计中采用了电容误差平均技术和增益自举运算放大器；为了实现低功耗设计，在电路设计中综合采用了运算放大器共享、输入采样保持放大器消去、按比例缩小和动态比较器等技术。在考虑工艺实现中的非理想因素的条件下，对ADC电路进行晶体管级Monte-Carlo仿真，当ADC以15MHz的采样率对1．1MHz的正弦输入信号进行采样转换时，在其输出得到了80．8dBc的非杂散动态范围（SFDR），并且此时ADC模拟部分的功耗仅为10mW。结果表明：该ADC达到了13b15MS／S的设计性能，实现了低功耗的设计目标。     

12bit 800MSPS电流舵结构的高速DAC设计

本文设计了一个分辨率为12位，采样频率为800MHz的高速电流舵结构DAC。该设计基于TSMC0．18umCMOS工艺，采用了二进制码控制和温度计码译码控制相结合的方式，从而在降低DNL误差和减小毛刺的同时，又能实现较小的芯片面积和功耗。为达到高的精度和高的转换速度，该设计在系统结构、电路结构以及芯片版图等方面都做了优化。     

一个用于GSM的80dB动态范围Σ-Δ调制器

设计了一个用于GSM系统的Sigma-Delta调制器. GSM系统要求信号带宽大于200kHz，动态范围大于80dB. 为了能取得较低的过采样率以降低功耗，采用了级联结构（MASH）来实现，与单环高阶结构相比，它具有稳定及易于实现的优点. 设计工作时钟为16MHz，过采样率为32，基带带宽为250kHz，电路仿真可以达到最高82dB的SNDR和87dB的动态范围. 芯片采用SMIC 0.18μm工艺进行流片，面积为1.2mm×1.8mm. 芯片测试效果最高SNDR＝74.4dB，动态范围超过80dB，测试结果与电路仿真结果相近，达到了预定的设计目标. 芯片工作在18V电源电压下，功耗为16.7mW.     

基于USB2.0的语音数据采集系统设计

本文提出并设计实现了基于USB2．0的语音数据采集系统，该系统以TMS320VC5402 DSP芯片为主控机，采用USB2．0协议芯片ISP1581实现系统与计算机之间的高速串行数据传输，重点介绍了USB设备主从两端的软硬件设计方案。     

一种高阶除法器的设计与实现

文章利用业界通用的fpspec92、fpspec95、linpack、whetstone．fl。Ps等浮点基准测试程序，基于阻塞步长对浮点处理性能进行分析。通过大量实验，得出浮点除法最佳执行周期为8～12拍。据此，为“龙腾R1”处理器设计了执行周期为11拍的基-56浮点除法器，并在SMIC0．181μm工艺下实现，恶劣环境下其运行速度为233MHz，面积约为0．174mm^2。     

非接触式IC卡射频前端电路设计

给出了一种基于 ISO/IEC1 44 4 3 -2标准的非接触式 IC卡射频前端电路设计方案 ,详细叙述了典型模块的设计思路。本设计采用 0 .8μm CMOS工艺流水 ,设计工作频率为 1 3 .5 6MHz,数据传输速率为 1 0 6kbps。文中给出了 Hspice模拟和相应的芯片测试结果 ,验证了设计     

窄带射频接收系统中带通∑-△调制器的设计

设计了一种适用于无线窄带射频接收系统的带通∑-△调制器，并将其成功集成于一个无线射频收发芯片之中。该调制器采用0．35μm CMOS工艺实现，采用斩波-稳零，动态元件匹配，以及正交采样等技术，提高系统的信噪比，并解决通道间失配的问题。模拟结果表明，该电路在30kHz带宽内，信噪比为83．4dB，而两个通道消耗的总电流仅为1mA。     

一种自校准的14-bit 100-MSPs 电流舵型DAC

本论文介绍了一种14-bit, 100MS/s CMOS数模转化器的设计与实现。引入了以模拟电流校准概念为基础模拟后台自校准技术。设计采用了恒定时钟负载开关驱动电路、校准周期随机化电路和输出自归零技术来提高DAC的动态性能。芯片利用中芯国际0.13-μm CMOS工艺实现,有效面积为1.33mm×0.97mm。数字和模拟电路分别在1.2/3.3V供电下工作,总的电流消耗为50mA。测试到的微分非线性和积分非线性分别为3.1LSB和4.3LSB。在100MHz采样频率,1MHz输入信号的工作条件下,测试得到的SFDR为72.8dB。     

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.