一种1.5 V 8.3×10-6/℃数字控制型CMOS带隙基准电压源

提出了一种新颖的带有数字控制的带隙基准电压源,此带隙基准电压源通过控制PNP晶体管的导通来实现可调的输出参考电压和可调的温度系数.此电路通过数字信号控制获得了一组不同的温度曲线,从这组温度曲线中,可以得到精确的输出参考电压和非常好的温度特性曲线.数字控制型带隙基准电压源的输出电压误差可以控制在±4 mV以内,最好的温度系数可以达到8.3×10-6/℃(温度从-40～80℃变化时),在电源电压从1.5～3.3 V变化时输出参考电压仅变化1 mV.所设计的带隙基准电压源,采用SMIC 0.18 μm CMOS工艺流片实现,面积为0.09 mm2.     

宽温范围高温度稳定性曲率互补电压基准设计

针对当前射频系统中电源管理芯片在宽温度范围下对带隙基准稳定性的较高要求,提出了一种新型互补带隙基准电路结构,通过将带隙基准与MOS弱反型区基准的温度系数曲率互补叠加,实现了极宽温度范围内带隙电压基准的高温度稳定性输出.采用0.35 μm CMOS工艺对所设计的电路进行了流片验证,测试结果表明,基准电压源工作电压为5V时,输出基准电压1.28 V,在-55 ～125℃温度范围内,温度系数可达4.5×10-6/℃,频率1 kHz时,电源抑制比(PSRR)可达-60 dB,100 kHz时,PSRR可达-55 dB,电压基准源芯片面积为0.22 mm×0.15 mm.     

一种高精度CMOS带隙基准电压源设计

介绍了带隙基准电压源的基本原理,设计了一种高精度带隙基准电压源电路.该电路采用中芯国际半导体制造公司0.18 μm CMOS工艺.Hspice仿真表明,基准输出电压在温度为-10～120 ℃时,温度系数为6.3×10-6/℃,在电源电压为3.0～3.6 V内,电源抑制比为69 dB.该电压基准在相变存储器芯片电路中,用于运放偏置和读出/写驱动电路中所需的高精度电流源电路.     

一种低温度系数高驱动能力的带隙基准电路

基于Grace 0.18μm标准CMOS工艺,设计了一种带低压差线性稳压器的低温度系数带隙基准源.仿真结果表明,在1.8V供电下,带隙基准电路从电源电压上抽取约340 μA电流,在-40℃～85℃温度范围内,输出电压为900.24 mV±0.222 mV,温度系数达到5×10-6/℃,在1kHz频率下,电源抑制比约为5...     

一种高精度CMOS带隙基准源的设计

分析了传统CMOS带隙基准源电路中三极管VBE电流随温度变化的二阶非线性效应,提出了一种对PTAT二阶温度进行补偿的方法,并在此基础上设计了一个高精度的带隙基准源电路.该电路采用SMIC 0.18 μm CMOS工艺实现,具有良好的温度系数和电源抑制比.Cadence Spectre仿真结果表明,该电路在-40～140 ℃的温度系数为7.7×10-6/℃,低频时的电源抑制比可达-76 dB,基准源电路的供电电压范围为2～4.5 V.     

一种低温漂BiCMOS带隙基准电压源的设计

文章介绍了一种低温漂的BiCMOS带隙基准电压源.基于特许半导体(Chartered)0.35 μm BiCMOS工艺,采用Brokaw带隙基准电压源结构,通过一级温度补偿技术,设计得到了一种在-40℃到 85℃的温度变化范围内温度系数为15.2×10-6/℃,输出电压为2.5 V±0.002 V的带隙基准电压源电路.±20%的电源电压变化情况下,输出电压变化为2.2 mV,电源电压抑制比为60 dB.5 V电源电压下功耗为1.19 mW.具有良好的电源抑制能力.     

采用二次曲线校正的CMOS带隙基准

利用MOS管饱和电流对于"过驱动电压"的平方关系,提出一种新颖的电压差平方电路,产生相对于温度差的二次项补偿量,对典型的CMOS带隙基准进行曲率校正,获得更小的温度系数.基于某标准0.5 μm CMOS工艺,在-40～120℃范围内,该方法将传统带隙基准的温度系数从21.4×10-6/℃减小到4.5×10-6/℃,电路的输入电压可以低至1.8 V,工作电流12 μA,输出基准电压可在0～1.2 V之间任意设置.该方法可在任何CMOS工艺或BiCMOS工艺中实现,具有很强的通用性.     

一种具有高电源抑制比的带隙基准电压源

根据带隙基准电压源理论,在传统CMOS带隙电压源电路结构的基础上,采用曲率补偿技术,对一阶温度补偿电路进行高阶补偿,获得了一种结构简单,电源抑制比和温度系数等性能都较好的带隙电压基准源.该电路采用CSMC 0.5 μm标准CMOS工艺实现,用Spectre进行仿真.结果表明,在3.3 V电源电压下,在-30 ℃～125 ℃范围内,温度系数为3.2×10-6 /℃;在27 ℃下,10 Hz时电源抑制比(PSRR)高达118 dB,1 kHz时(PSRR)达到86 dB.     

高电源抑制比带隙基准电压源的设计

提出一种采用0.25 μm CMOS工艺的低功耗、高电源抑制比、低温度系数的带隙基准电压源(BGR)设计.设计中,采用了共源共栅电流镜结构,运放的输出作为驱动的同时也作为自身电流源的驱动,并且实现了与绝对温度成正比(PTAT)温度补偿.使用Hspice对其进行仿真,在中芯国际标准0.25 μm CMOS工艺下,当温度变化范围在-25～125℃和电源电压变化范围为4.5～5.5 V时,输出基准电压具有9.3×10-6 V/℃的温度特性,Vref摆动小于0.12 mV,在低频时具有85 dB以上的电源电压抑制比(PSRR),整个电路消耗电源电流仅为20μA.     

一种具有大电流驱动能力的低温漂带隙基准电压源

基于XFAB 0.6 μm CMOS工艺,设计了一种具有大电流驱动能力的低温度系数带隙基准电压源。通过设置不同温度系数的电阻的比值,实现带隙基准的2阶曲率补偿。采用新的电路结构,使基准源具有驱动10 mA以上负载电流的能力。经过Hspice仿真验证,常温基准输出电压为2.496 V,-55 ℃~125 ℃温度范围内的温度系数是3.1×10-6/℃;低频时,电源电压抑制比为-77.6 dB;供电电压在4~6 V范围内,基准输出电压的线性调整率为0.005%/V;负载电流在0~10 mA范围内,基准输出电压波动为219 μV,电流源负载调整率为0.022 mV/mA。     

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.