MOCVD生长GaAs／AlxGa1—xAs多量子阱子带间红外吸收特性

对ＭＯＣＶＤ生长的ＧａＡｓ（４０Ａ）／ＡｌｘＧａ１－ｘＡｓ（３００Ａ）多量子阱结构观察到阱内电子从基态到第一激态跃迁引起的红外吸收。用Ｂｒｕｋｅｒ红外光谱仪测量，发现了一个峰值在９８６ｃｍ＾－１（１０．１μｍ）带宽为２３７ｃｍ＾－１（９～１１．５μｍ）的强吸收峰，该峰位置与阱内电子从基态到第一激发态跃迁所计算的吸收峰位置基本一致。     

Ge和GaAs线膨胀系数和能隙的温度关系

用３个特征频率的爱因斯坦模型，以Ｇｒｕｎｅｉｓｅｎ参数γｉ和约化的电子－声子耦合强度（ｇ＾２Ｆ）Ｗｉ为参数，较好地拟事子Ｇｅ和ＧａＡｓ的线膨胀系数与能隙的温度关系的实验曲线，结果表明ＴＡ的声子的负的Ｇｒｕｎｅｉｓｅｎ参数是引起低温区Ｇｅ和ＧａＡｓ的线膨胀系数反常的原因，同时，Ｇｅ和ＧａＡｓ的价带项状态的（ｇ＾２Ｆ）ｗｉ为正值，而导带底状态的相应量为负值。     

MBE生长轻掺Si高迁移率GaAs材料的杂质补偿特性研究

本文报道了用ＭＢＥ生长轻掺Ｓｉ高迁移率ＧａＡｓ材料的杂质补偿特性实验研究．已得到７７Ｋ温度下迁移率为１６．２e４ｃｍ２／（Ｖ·ｓ）的ＧａＡｓ材料．样品的Ｈａｌｌ测量结果表明：在较低的杂质浓度范围（１e１３ｃｍ－３＜ｎ＜１e１５ｃｍ－３）内，在大体相同的生长温度（５９０℃左右）下，选择适当的生长速率Ｇｒ会增强对浅受主杂质的抑制作用，同时也会抑制Ｓｉ的自补偿效应，减小杂质的补偿度Ｎａ／Ｎｄ之值，从而提高ＭＢＥ外延ＧａＡｓ材料的迁移率．     

Si_（1－x）Ge_x合金的浅杂质光电导谱

在４．２—５０Ｋ温度范围内研究了直拉法生长的富含Ｓｉ的Ｓｉ（１－ｘ）Ｇｅｘ合金的浅杂质光电导谱，首次观察到了锗硅合金中从硼受主杂质基态到ｐ３／２价带的光电离跃迁过程及硼受主杂质的与自旋－轨道分裂带（ｐ１／２价带）相联系折光电导过程，并由此确定了硼杂质的电离能．结果表明，低锗组分下，Ｓｉ（１－ｘ）Ｇｅｘ合金中浅受主杂质电离能随合金组分线性变化．     

In0.53Ga0.47As表面钝化及降低界面态密度的方法

采用ＰＥＣＶＤ技术，以ＴＥＯＳ为源，对Ｉｎ０．５３Ｇａ０．４７Ａｓ材料进行表面钝化，研究了ＳｉＯ２／Ｉｎ０．５３Ｇａ０．４７Ａｓ的界面态，提出降低界面态密度的方法，使其降低到８．５×１０＾１０ｅＶ＾－１ｃｍ＾－２。     

Er,O离子共注入GaAs的二次离子质谱的研究

在Ⅲ－Ⅴ族半导体ＧａＡｓ外延层上共注入Ｅｒ和Ｏ离子（ＧａＡｓ：Ｅｒ，Ｏ）．经面对面优化退火后，光致发光（ｐｈｏｔｏｌｕｍｉｎｅｓｃｅｎｃｅ－ＰＬ）谱中观测到对应Ｅｒ３＋第一激发态到基态４Ｉ１３／２－４Ｉ１５／２跃迁，其相对强度较单注入Ｅｒ的ＧａＡｓ（ＧａＡｓ：Ｅｒ）增强１０倍，且谱线变窄．从二次离子质谱（ＳｅｃｏｎｄａｒｙＩｏｎＭａｓＳｐｅｃｔｒｏｍｅｔｒｙ－ＳＩＭＳ）和卢瑟福背散射实验给出退火前后Ｅｒ在ＧａＡｓ：Ｅｒ样品中的剖面分布．ＳＩＭＳ测量分别给出Ｏ注入前后Ｅｒ和Ｏ在ＧａＡｓ：Ｅｒ，Ｏ中的深度剖面分布，分析表明Ｅｒ和Ｏ共注入后形成光学激活有效的发光中心．     

带－带跃迁时的“热”电子激光器

带－带跃迁时的“热”电子激光器文献［１］首次讨论了Ｅ０．１ｅＶ的“冷”冲击电子（）激光器思想，其电子能量小于超晶格的势垒高度Ｕ０，在准带间跃迁。文献［２，３］首次展示了在注入ＧａＡｓ中获得Ｅ０．１～０．３“热”电子的可能性，电子的射程达到（２～３）·...     

3～5.3μmIn_xGa_(1-x)As/Al_yGa_(1-y)As/Al_zGa_(1-z)As非对称台阶量子阱红外探测器

本文报道我们率先研制出的３～５．３μｍＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱红外探测器的制备和性能．该探测器具有光伏特征，７７Ｋ温度、±７Ｖ外偏压下的５００Ｋ黑体探测率达到约１．０×１０１０ｃｍ·Ｈｚ１／２／Ｗ，并且，与１→２子带间跃迁相对应的光电流峰值响应波长可随外偏压在中红外（３～５．３μｍ）波段作适当调谐．运用平面波展开法，依据样品的阱、垒结构参数，计算了ＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱１→２子带间跃迁的Ｓｔａ     

GaAs MESFET中肖特基势垒接触退化机理的研究

本文对Ｔｉ／Ｍｏ／Ｔｉ／Ａｕ作为栅金属的ＧａＡｓＭＥＳＦＥＴ进行了四种不同的应力试验：１．高温反偏（ＨＴＲＢ）；２．高压反偏（ＨＲＢ）；３．高温正向大电流（ＨＦＧＣ）；４．高温存贮（ＨＴＳ）．通过ＨＲＢ，ΦＢ从０．６４ｅＶ减少到０．６２ｅＶ，理想因子ｎ略有增大．ＨＴＳ试验中ΦＢ从０．６７ｅＶ增加到０．６９ｅＶ．分析表明，这归因于界面氧化层的消失，以及Ｔｉ与ＧａＡｓ的反应；ＨＦＧＣ试验结果表明其主要的失效模式为烧毁，ＳＥＭ观察中有电徙动及断栅现象发生．ＡＥＳ分析表明。应力试验后的样品，肖特基势垒接触界面模糊     

用XPS对CdTe（111）面进行化学特性分析

用ＸＰＳ化学位移和定量分析方法，研究了露于室温空气中的ＣｄＴｅ（１１１）面的化学特征。首次报道了经机械抛光表面上形成的表面化合物为ＴｅＯ２（Ｔｅ３ｄ５／２５７５．８ｅＶ，Ｏ１ｓ５３０．１ｅＶ）和Ｃｄ（ＯＨ）２（Ｃｄ３ｄ５／２４０５１ｅＶ．Ｏ１ｓ５３１．４ｅＶ）。并与基体里的ＣｄＴｅ共存；经２％Ｂｒ－乙醇溶液化学抛光，表面上形成的化合物为ＣｄＴｅＯ４（Ｃｄ３ｄ５／２４０５．３ｅＶ，Ｔｅ３ｄ５／２５７６５ｅＶ，Ｏ１ｓ５３１．２ｅＶ）和ＴｅＯｘ（ｘ＜１）（Ｔｅ３ｄ５／２５７４～５７５ｅＶ，Ｏ１ｓ５２８１ｅＶ），并且ＸＰＳ谱中没有基体里的ＣｄＴｅ的特征，其中ＴｅＯＸ为Ｔｅ氧化物的过渡态。结果表明，在相同氧化环境中，表面上形成的化合物强烈依赖表面状况。     

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-