Ⅱ—Ⅵ族半导体特性参数的三维边缘元分析

本文用三维边缘元方法分析了电导率为张量的有间隙Ⅱ－Ⅵ族半导体材料的散射特性,给出了散射参数与半导体特性参数之间的关系曲线并了用这些曲线确定Ⅱ－Ⅵ族半导体电牧场生参数的方法,该方法直接从泛函变分出发,避开了其它方法中示解有损超薄各向异性介质充波导本征值问题的困难,简化了求解过程,计算结果与实验值的比较证实了本方法具有有效、可靠和精确的特点。     

有间隙Ⅱ－Ⅵ族半导体材料散射特性的三维边缘元分析

用三维边缘元方法分析了有间隙Ⅱ－Ⅵ族半导体材料的散射特性．该方法直接从泛函变分出发，避开了其它方法中求解有损超薄介质填充波导本征值和本征函数的困难，简化了求解过程．计算结果与实验值的比较证实了本方法具有有效、可靠和精确的特点     

有间隙Ⅱ—Ⅵ族半导体材料散射特性的三维边缘元分析

用三维边缘元方法分析了有间隙Ⅱ－Ⅵ族半导体材料的散射特性，该方法直接从泛函变分出发避开了其它方法中示肯损超薄介质填充波导本征值和本片函数的困难，简化了求解过程，计算结果与实验值的比较证实了本方法具有有效，可靠和精确的特点。     

Ⅱ—Ⅵ族半导体材料散射特性的高次有限元分析

用有限元和场匹配相结合的方法分析了Ⅱ-Ⅵ族半导体材料的散射特性。该方法能一次求出纵向模匹配所需要的所有本征模函数,并避开了多模网络方法中求解复超越方程的困难,简化了求解过程。本方法和多模网络方法计算的结果与多个样品的测试值进行了比较,彼此吻合得很好,表明本文方法不仅通用精确,而且具有很高的解题效率。     

Be基蓝绿激光器载流子约束的LCAO理论研究

本征的强离子性，使ZnSe基半导体蓝绿激光器易于形成堆垛层错等退化缺陷，严重地影响了器件的寿命。人们便开始将注意力投向离子性较低的Be基化合物，希望用Be基Ⅱ-Ⅵ族材料取代ZnSe基材料，抑制蓝绿激光器的退化。要研制半导体激光器，电学限制层对发光活性层中载流子的约束能力（即能带的offset值）是最重要的基本参数之一。由于对Be基化合物的了解十分有限，本文从基本的原子参数出发，用原子轨道线性组合（LCAO）理论计算了所有Ⅱ-Ⅵ族化合物价带顶的相对位置，结合带隙的实验值，给出了Ⅱ-Ⅵ族化合物导带底的相对位置。简要分析了二元化合物用于BeTe中载流于约束的可能性。根据虚晶近似，用插值方法计算了与GaAs匹配的Be基四元合金相对与BeTe价带、导带的offset。对各四元合金的特征进行了分析对比，讨论了Be基四元合金用作我流子约束层的可能性。为制作Be基半导体蓝绿激光器提供了能带剪裁的理论依据。     

用于Ⅱ-Ⅵ族半导体材料光学双稳特性测试装置

本文介绍了研究Ⅱ-Ⅵ族半导体超晶格光双稳特性的实验装置以及实验结果。     

1988中心专利选刊

在衬底上生长Ⅱ-Ⅵ族半导体化合物薄膜DD251-153-A在碲熔融液中的衬底上生长电致发光或阴极射线发光器件的Ⅱ-Ⅵ族半导体材料发光膜,衬底最好是具备蒸镀绝缘膜和高熔点金属(Ni,Au,W,Mo)丝的石英膜片。其特点是用过渡族金属掺杂Ⅱ-Ⅵ族化合物。这种过渡族金属是锰或某种稀土金属,其浓度为0.01-100atom％.可以以金属或硫化物的方式添加。Ⅱ-Ⅵ族化合物是ZnS,CsS,ZnSe,CaS,MgS;混合化合物是(Zn,     

Ⅱ-Ⅵ族半导体纳米晶体的掺杂研究进展

介绍了Ⅱ-Ⅵ族半导体纳米晶体的掺杂技术和几种典型的掺杂工艺;综述了掺杂对半导体纳米晶体的光、电特性的影响;列举了近几年掺杂技术取得的研究成果;重点阐述了现阶段利用胶体法进行半导体纳米晶体掺杂的掺杂机理、以及掺杂效率所存在的问题。引进新型掺杂理论——动力学理论,该模型忽略了扩散作用的影响,重点讨论杂质在纳米晶体表面的驻留情况,可以有效解释Ⅱ-Ⅵ族纳米半导体的掺杂机理,提高掺杂浓度。最后,对其未来的发展方向进行了展望,指出开创新型掺杂理论、研发实用化掺杂工艺以及拓展应用领域是未来Ⅱ-Ⅵ族纳米半导体的主要研究方向。     

Ⅱ-Ⅵ族半导体纳米晶体的掺杂研究进展

介绍了Ⅱ-Ⅵ族半导体纳米晶体的掺杂技术和几种典型的掺杂工艺;综述了掺杂对半导体纳米晶体的光、电特性的影响;列举了近几年掺杂技术取得的研究成果;重点阐述了现阶段利用胶体法进行半导体纳米晶体掺杂的掺杂机理、以及掺杂效率所存在的问题。引进新型掺杂理论——动力学理论,该模型忽略了扩散作用的影响,重点讨论杂质在纳米晶体表面的驻留情况,可以有效解释Ⅱ-Ⅵ族纳米半导体的掺杂机理,提高掺杂浓度。最后,对其未来的发展方向进行了展望,指出开创新型掺杂理论、研发实用化掺杂工艺以及拓展应用领域是未来Ⅱ-Ⅵ族纳米半导体的主要研究方向。     

Ⅱ一Ⅵ族半导体纳米晶体的掺杂研究进展

介绍了Ⅱ-Ⅵ族半导体纳米晶体的掺杂技术和几种典型的掺杂工艺;综述了掺杂对半导体纳米晶体的光、电特性的影响;列举了近几年掺杂技术取得的研究成果;重点阐述了现阶段利用胶体法进行半导体纳米晶体掺杂的掺杂机理、以及掺杂效率所存在的问题.引进新型掺杂理论--动力学理论,该模型忽略了扩散作用的影响,重点讨论杂质在纳米晶体表面的驻留情况,可以有效解释Ⅱ-Ⅵ族纳米半导体的掺杂机理,提高掺杂浓度.最后,对其未来的发展方向进行了展望,指出开创新型掺杂理论、研发实用化掺杂工艺以及拓展应用领域是未来Ⅱ-Ⅵ族纳米半导体的主要研究方向.     

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.     

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.     

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.     

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.     

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     

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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