利用I2V 正向特性提取PN 二极管主要参数的研究

研究了利用电流－电压（I－V）正向特性提取PN结二极管参数的方法，与通常使用的PN结二极管模型不同，本文模型考虑了并联电导对电流的影响，在I－V特性曲线上读取四级（V，I）值，用牛顿法对模型方程组进行数值求解，可提取出PN结二极管的主要参数：反向饱和电流，串联电阻，发射系数以及并联电导。结果表明，该方法简便，实用。     

大束流离子注入形成P-Si CoSi2/Si肖特基结的电学特性

采用金属离子注入法形式 Co Si2 /Si肖特基结并分析电学特性。分别测量不同退火条件下样品的 I-V、C-V特性 ,得出了各样品的势垒高度、串联电阻和理想因子。结果表明 ,采用快速热退火方法形成的结性能较好     

Al-Si接触的快速热退火

本文报道了用常规管式炉30秒钟快速热退火代替常规热合金化做Al-Si欧姆接触的简捷方法.通过俄歇电子能谱、扫描电子显微镜、接触电阻率和PN结反向电流的研究证实该法能有效地抑制导致浅结器件失效的Al-Si互扩散现象,从而达到保持良好结特性的欧姆接触.     

PN型半导体电特性分析

基于PN结半导体的理论知识,详细的介绍了PN结半导体的工作原理,通过实验描绘出了PN结伏安特性曲线,并利用基本理论知识对大学实验中＂非线性电阻元件＂的伏安特性进行解释。     

分子束外延P-on-N HgCdTe As扩散调控研究

对分子束外延（MBE）生长的原位As掺杂HgCdTe外延材料的热退火造成的As扩散控制进行研究。在较低的退火温度下获得了As扩散长度可控的HgCdTe材料,易于形成符合设计参数的PN结轮廓,为后续新型焦平面器件的研发提供基础。研究发现,在热退火过程中,原位As掺杂HgCdTe的As浓度的大小和纵向分布随着不同的Hg分压而发生改变。并通过理论计算获得了不同Hg分压下的As扩散系数。同时,通过数值模拟对不同As扩散长度的P-on-N器件结构进行了暗电流模拟,验证了As掺杂结深推进工艺的重要性。     

硅PN结反向击穿冷阴极研究

本文报导了硅PN结反向击穿冷阴极电子发射源的研究结果。尽管器件制造中采用的大部分工艺与标准的微电子工艺相容,但为了形成和测量超薄PN结,还引入了一些特殊方法。这些方法包括:超低能离子注入,由氧化和腐蚀构成的结区减薄工艺,快速热退火和一些对工艺进行监测的新方法。本文给出了电子发射特性,最大发射电流达到150nA,它对应的发射效率为8×10~(-6),这个数值已达到国际水平。     

快速热退火对锑化铟表层化学配比的影响

锑化铟是一种窄禁带化合物半导体。近几年,它作为3～5μm红外探测器阵列的一种材料受到广泛的重视。为了制备高质量的锑化铟PN结光电二极管,铍注入与快速热退火(RTA)技术相结合是一种最佳的选择。本文借助俄歇电子能谱(AES)对在快速退火条件下锑化铟表层化学配比的偏离进行了系统的研究。     

Discussion on

利用受光PN结伏安特性方程,分别对受光PN结的光电流输出、注入电流输出和零电流输出三种情况进行了讨论,进一步对注入光敏器件的物理基础进行探讨,并对一些实验问题进行讨论。     

对"四论注入光敏器件的物理基础"一文的商榷

利用受光PN 结伏安特性方程,分别对受光PN 结的光电流输出、注入电流输出和零电流输出三种情况进行了讨论,进一步对注入光敏器件的物理基础进行探讨,并对一些实验问题进行讨论。     

大功率LED伏安特性模型研究

研究了大功率LED芯片的伏安特性。基于LED 芯片的特殊性,从经典的PN结伏安特性出发,进行理论推导并通过选择不同的基函 数,构建出了大功率LED芯片的伏安特性新 模型和优化模型,模型中的系数采用最小二乘法进行确定。对大功率LED芯片的实测 伏安特性数据表明,本文构建出的优化模型比经典的PN结模型更能准确表征LED的伏安特性 ,与实测的伏安特性数据一致性更高,更具实用价值。     

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.     

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.     

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.     

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.     

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.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-