一种低电压的CMOS带隙基准源

设计了一种用于集成电路内部的带隙基准源，采用了1．0V／0．18μmCMOS工艺。该电路利用电阻分压和高阶温度补偿，达到降低温度率数的目的，并具有好的电源抑制比。SPICE仿真结果表明，在0℃-100℃范围内度可达到18ppm/℃，其电源抑制比可达到62dB。     

一种新型无运放CMOS带隙基准电路

介绍了带隙基准原理和常规的带隙基准电路,设计了一种新型无运放带隙基准电路。该电路利用MOS电流镜和负反馈箝位技术,避免了运放的使用,从而消除了运放带隙基准电路中运放的失调电压和电源抑制比等对基准源精度的影响。该新型电路比传统无运放带隙基准电路具有更高的精度和电源抑制比。基于0.18μm标准CMOS工艺,在Cadence Spectre环境下仿真。采用2.5V电源电压,在-40℃～125℃温度范围的温度系数为6.73×10-6/℃,电源抑制比为54.8dB,功耗仅有0.25mW。     

一种低温度系数带隙基准电压源

描述了一个具有高电源抑制比和低温度系数的带隙基准电压源电路。基于1阶零温度系数点可调节的结构,通过对不同零温度系数点带隙电压的转换实现低温度系数,并采用了电源波动抑制电路。采用SMIC 0.18μm CMOS工艺,经过Cadence Spectre仿真验证,在-20℃～100℃温度范围内,电压变化范围小于0.5mV,温度系数不超过7×10-6/℃。低频下的电源抑制比为-107dB,在10kHz下,电源抑制比可达到-90dB。整个电路在供电电压大于2.3V时可以实现正常启动,在3.3V电源供电下,电路的功耗约为1.05mW。     

一种带隙基准电压源的设计

经分析带隙基准电压源的温度补偿原理，进行一阶温度补偿，然后提出了新型的二阶温度补偿的方法，用Hspice仿真，得到温度系数为5ppm／℃，电源抑制比可达到60dB，取得了比较理想的效果。     

一种新型无运放的带隙基准电路

设计了一种新型无运放的带隙基准电路,利用电流镜和负反馈技术省去了运放,消除了运放带隙基准电路中失调电压对基准精度的影响,提升了电源抑制比。相比于传统的无运放带隙基准结构,该新型电路具有更高的精度和电源抑制比。基于0.35μm的BCD工艺,在Cadence Spectre环境下进行了仿真。在5 V电源电压下,电源抑制比为79 d B,-40~125℃温度范围内的温度系数为4.2×10-6/℃。     

采用电阻补偿的高PSRR基准电压源设计

与传统的带隙基准电路完全使用p-n结达到高次温度补偿不同,提出利用标准CMOS工艺下不同电阻的不同温度系数,实现温度的高次补偿,大大减小了电路的复杂性和功耗.同时,通过增加电源电压耦合电路,提高电源抑制比,并在输出级利用低压差电压DC转换电路,实现电压转换,提供可调的多种参考电压.该电路采用Chartered 0.35 μm CMOS 工艺实现,采用3.3 V电源电压,在-40～100 ℃范围内,达到低于6 ppm/℃的温度系数,在1 kHz和27 ℃下,电源抑制比达到82 dB.     

一种高精度高电源抑制比的带隙基准电压源的设计

设计了一种具有良好稳定性和高精度的带隙基准电压源电路。通过启动电路和提高电源抑制比电路的加入,使得带隙基准电压具有较高的电源电压抑制比和较小的温度系数。HSPICE仿真结果表明,在电源电压V_(DD)=3．3V时,在-55℃～125℃的温度范围内,电路得到一个温度系数仅为17×10~(-6)/℃,电源抑制比(PSRR)为79dB的带隙基准电压输出。     

可用于电视系统的带隙基准电压源设计

针对传统一阶温度补偿的CMOS带隙基准电压源的温度特性较差的问题,在此基础上采用高阶温度补偿以改善温度特性,并且在电路中增加了带有负反馈的前调整器,提高了基准电压的电源抑制比.对电路采用SMICO.18CMOS工艺进行仿真,输出电压在温度为-20℃～+58℃范围内有负的温度系数2.34×10-6/℃,在温度为58℃～120℃范围内有正的温度系数为2.21×10-6/℃,在低频时电源抑制比可达116 dB,在10 kHz时也可达到73 dB.     

一种1.8V24×10-6/℃宽温度范围CMOS带隙基准电压源

阐述了一种输出电压为853 hV的带隙基准电压源电路,该电路采用0.18μm标准CMOS工艺实现,可在1.8 V的电源电压下工作,在-20℃到120℃温度范围内其温度系数为24×10-6/℃.在频率低于10kHz时,电源抑制比保持在-66dB.电路版图的有效面积为0.022 mm2.该电路已成功应用于低功耗CMOS图象传感器芯片当中.     

一种CMOS工艺低电压带隙基准源

基于0.18μm CMOS工艺,设计了一种低电源电压的带隙基准源.该带隙基准源电路采用非线性温度补偿,具有很高的温度稳定性.Hspice仿真结果显示,电源电压最低为1.2V时,在-40～135℃的温度范围内,输出电压在556.03～556.26mV之间变化,平均温度系数约仅为2.36ppm/℃,电源电压抑制比可达到90dB.     

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.     

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.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its