一种高精确度低功耗无片外电容LDO设计

设计了一种片上集成的高精确度、低功耗、无片外电容的低压差线性稳压器(LDO)。采用一种新型高精确度、带隙基准电压源电路降低输出电压温漂系数;采用零功耗启动电路和支路较少的摆率增强模块降低功耗,该电路采用CSMC 0.5 μm CMOS工艺。经过Cadence Spectre仿真验证,输出电压为3.3 V,在3.5~5.5 V范围内变化时,线性调整率小于0.3 mV/V,负载调整率小于0.09 mV/mA,输出电压在-40~+150 ℃范围内温漂系数达10 ppm/℃,整个LDO消耗17.7 μA的电流。     

一种改进型低温度系数带隙基准源电路

在传统带隙基准源的基础上,设计了一种改进型带隙基准源电路,能很好地抑制三极管集电极电流变化对输出的影响,获得很低的温度系数和很高的电源电压抑制比。基于BCD 0.18 μm工艺库,仿真结果表明,当电源电压VIN为4.5 V,温度范围为-40 ℃~140 ℃时,基准源电路的输出电压范围为1.2567~1.2581 V,温度系数为6.3 ×10-6/℃;电源电压在2.5~5 V范围内变化时,基准源电路输出的最大变化仅为1.66×10-4 V,线性调整率为0.006 64 %;低频电源电压抑制比高达97 dB。过温保护电路(OTP)仿真表明,该基准源电路有良好的温度特性,温度不高于140 ℃都可正常工作。     

双极型高精度大负载电流集成电压基准源设计

设计并实现了一种基于双极型工艺的2.5V高精度大负载电流集成基准电压源电路,通过对传统带隙基准电路的改进,设计中增加了电源电压分配电路、电流反馈电路和大电流驱动电路,实现高精度大负载电流的目标.通过Cadence软件平台下的Spectre仿真器对电路的温度系数、负载调整率、噪声、交流电源纹波抑制比、负载电流、启动时间等电参数进行仿真验证,得到了初始精度±0.5%,在-40～85℃范围内温度系数小于6×10-6/℃,负载电流0～50 mA,电源电压4.5～36 V,输出为2.5 V的集成电压基准源电路.该电路采用6 μm/36 VK极型工艺生产制造,芯片面积为1.7 mm×2.1 mm,具有过热保护、过流保护和反接保护功能.     

低温漂带隙基准源及驱动电路设计

基于标准N阱CMOS工艺设计了一种带隙基准电压产生及输出驱动转换电路。该电路采用0.6μmCSMC-HJN阱CMOS工艺验证,HSPICE模拟仿真结果表明电路输出基准电压为1.25V左右;在–55℃～125℃温度范围内的典型工艺参数条件下,电路温度系数仅为7×10-6/℃;电源电压范围为4V￣6V,在产生标称1.25V基准电压的同时,可以为负载提供1mA￣2mA的电流驱动能力。     

一种4阶曲率补偿低温漂低功耗带隙基准源

基于UMC 0.25 μm BCD工艺,设计了一种4阶曲率补偿的低温漂带隙基准电压源。通过设置正负温度系数相异的电阻的比值,抵消了三极管发射极-基极电压泰勒级数展开后的高阶项,实现了4阶曲率补偿。经过Hspice仿真验证,基准输出电压为1.196 V,-40 ℃~150 ℃温度范围内温度系数达到1.43×10-6/℃;低频时电源抑制比为-70.8 dB,供电电压在1.7~5 V变化时,基准输出电压的线性调整率为0.039%,整体静态电流仅为9.8 μA。     

一种温度系数低于1×10-6/℃的带隙基准电压源

提出了一种温度系数低于1×10-6 /℃的曲率补偿带隙基准电压源。采用正温度系数电压对具有互补温度系数的BJT射-基极电压进行1阶补偿,向BJT射极注入互补温度系数电流,在输出电流中引入曲率正补偿项Tln T,以实现高阶温度补偿。同时,提出了一种新型曲率补偿的低压实现电路。基于标准0.18 μm CMOS工艺进行电路设计。仿真结果表明,在-40 ℃~125 ℃范围内,常压、低压带隙基准电压源的温度系数分别为3.48×10-7 /℃和4.73×10-7 /℃,电源抑制比分别为-73 dB和-60 dB,最大消耗电流分别为22 μA和19 μA。该新型低压曲率补偿带隙基准电压源的工作电压为0.9 V,面积为0.019 8 mm²。     

一种带曲率补偿的高精度带隙基准源设计

基于OKI 0.5 μm BCD工艺,设计了一种带曲率补偿的低温漂带隙基准源。采用Brokaw带隙基准核心结构,引入一个高阶效应的电流,对基准进行补偿。结合基准核心电路产生的无温度系数电压,利用简单的电路实现基准电流源的产生。仿真结果表明,在4.5 V供电电压下,-40 ℃~150 ℃温度范围内,基准电压的波动范围为1.1755~1.17625 V,温漂为3.9 ×10-6/℃,基准电流为3.635 μA,输出基准电流波动仅为2.2 nA,精度较高,低频时电路电源抑制比为-76 dB。     

一种低功耗曲率补偿带隙基准电压源

设计了一种低功耗曲率补偿带隙基准电压源。利用亚阈值MOS管差分对,产生曲率补偿电流,对输出基准电压进行曲率补偿。采用低功耗运放来增强基准电压源的电源抑制能力,同时降低基准电压源的功耗。采用SMIC 0.18 μm 混合信号CMOS工艺进行设计。仿真结果表明,在1.5 V电源电压下,基准电压源的输出基准电压为1.224 V,在-40 ℃~125 ℃范围内的温度系数为1.440×10-6/℃~4.076×10-6/℃,电源抑制比为-77.58 dB,消耗电流为225.54 nA。     

一种可修调的高精度低温漂带隙基准电压源

设计了一种可修调的高精度、低温漂、高电源电压抑制比的高阶温度补偿带隙基准电压源。在Brokaw型带隙基准电路结构的基础上,采用多晶硅电阻负温度系数补偿技术,可实现2阶曲率温度补偿,减小了基准电压的温漂;设计了电阻修调网络,保证了基准电压的高精度。电路基于标准双极工艺进行设计和制造,测试结果表明:在－55 ℃~125 ℃温度范围内,15 V电源电压下,基准源输出电压为2.5(1±0.24%) V,温度系数为1.2×10－5/℃,低频时的电源电压抑制比为－102 dB,静态电流为1 mA,重载时输出电流能力为10 mA。     

一种高精度二阶温度补偿带隙基准电路设计

基于通过负温度系数电压控制工作于亚阈值区MOS管栅压产生随温度变化的补偿电流原理,采用中芯国际0.18μm CMOS工艺,设计了一款高精度二阶温度补偿带隙基准电压源。测试结果表明,当电源电压大于1.6V时,电路能够产生稳定的1.21V输出电压;在电源电压为1.6~3.4V,-20~135℃温度范围内,最小温度系数为2×10-6/℃,最大温度系数为3.2×10-6/℃;当电源电压在1.6~3.4V之间变化时,输出电压偏差为0.6mV,电源调整率为0.34mV/V;在1.8V电源电压下,电源抑制比为69dB,因此能够适应于高精度基准源。     

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.     

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.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.