OTS修饰的不同厚度酞菁铜OTFT的研究

用十八烷基三氯硅烷(OTS)修饰了不同厚度的酞菁铜(CuPc)有机薄膜晶体管器件, 对比酞菁铜厚度为15、40、80 nm的3种器件性能后,得到40 nm的酞菁铜器件具有最高载流子迁移率.分析了OTS修饰的绝缘层表面对器件性能的影响,得到的40 nm厚度酞菁铜器件载流子迁移率为4.3×10-3cm2/V*s, 阈值电压为-9.5 V.     

具有无机有机双绝缘层和修饰电极的薄膜晶体管

研究了有机薄膜晶体管器件.器件是以热生长的SiO2作为有机薄膜晶体管的栅绝缘层,酞菁铜作为有源层的.实验表明采用一种硅烷耦合剂-十八烷基三氯硅烷(OTS)修饰SiO2可以有效地降低栅绝缘层的表面能从而明显提高了器件的性能.器件的场效应迁移率提高了2.5倍、阈值电压降低了3 V、开关电流比从103增加到104.同时我们采用MoO3修饰铝作为器件的源漏电极,形成MoO3/Al双层电极结构.实验表明在同样的栅极电压下,具有MoO3/Al 电极的器件和金电极的器件有着相似的源漏输出电流Ids.结果显示具有OTS/SiO2双绝缘层的及MoO3/Al 电极结构的器件能有效改进有机薄膜晶体管的性能.     

高性能有机薄膜晶体管(OTFT)制备及其导电机制

详细介绍了在SiO2和高kHfO2介质层上制备并五苯薄膜晶体管方面的研究,特别是利用原子力显微技术(AFM)和静电力显微技术(EFM)研究了并五苯分子初始生长模式,揭示了衬底形貌、表面化学性能(包括化学清洗和聚合物层修饰)对有机半导体成膜结构和薄膜场效应晶体管性能之间的关联,包括晶体管迁移率、开关比和阈值电压等;针对并五苯初始生长成核模式的差异,分析了不同岛(畴)间畴边界对载流子在有机薄膜内输运的影响,有助于理解有机半导体薄膜导电机理。通过优化和控制介电层和有机半导体薄膜层的界面化学性质,在SiO2介质层上成功制备出迁移率为1.0cm2/V.s、开关电流比达到106的OTFT器件;在高kHfO2介质层上获得的OTFT器件的工作电压在-5V以下,开关电流比达到105,载流子迁移率为0.6cm2/V.s;器件性能指标已经达到目前国际上文献报道的最好水平。     

表面修饰的ZnPc薄膜晶体管性能研究

以热生长的SiO2作为栅绝缘层,酞菁锌(ZnPc)作为有源层,研究了具有十八烷基三氯硅烷(OTS,C18H37SiCl3)/SiO2双绝缘层结构的有机薄膜晶体管(OTFT)。实验表明,采用OTS可以有效地降低SiO2栅绝缘层的表面能并改善表面的平整度,器件的场效应迁移率提高了3.5倍,漏电流从10-9A降到10-10A,阈值电压降低了5 V,开关电流比从103增加到104。结果显示,具有OTS/SiO2双绝缘层的器件结构能有效改进OTFT的性能。     

高性能顶栅结构有机薄膜晶体管

采用六联苯(p-6P)和氧钒酞菁(VOPc)作为有源层材料,利用弱外延生长技术制备有机薄膜晶体管(OTFT)。在相同的工艺条件下制备了顶栅结构(top-gate)和底栅结构(bottom-gate)两种器件构型,发现两种不同结构的OTFT器件特性存在较大的差异,top-gate OTFT的迁移率比bottom-gate OTFT高很多。在顶栅结构的器件构型中获得了较高的器件特性参数,迁移率达到1.6cm2/V.s。研究了弱外延生长技术应用在两种不同器件构型中的差异,并解释了顶栅结构OTFT迁移率较高的原因。     

高性能有机薄膜晶体管（OTFT）制备及其导电机制

详细介绍了在SiO2和高kHfO2介质层上制备并五苯薄膜晶体管方面的研究,特别是利用原子力显微技术（AFM）和静电力显微技术（EFM）研究了并五苯分子初始生长模式,揭示了衬底形貌、表面化学性能（包括化学清洗和聚合物层修饰）对有机半导体成膜结构和薄膜场效应晶体管性能之间的关联,包括晶体管迁移率、开关比和阈值电压等;针对并五苯初始生长成核模式的差异,分析了不同岛（畴）间畴边界对载流子在有机薄膜内输运的影响,有助于理解有机半导体薄膜导电机理。通过优化和控制介电层和有机半导体薄膜层的界面化学性质,在SiO2介质层上成功制备出迁移率为1.0cm^2/V.s、开关电流比达到10^6的OTFT器件;在高kHfO2介质层上获得的OTFT器件的工作电压在-5V以下,开关电流比达到10^5,载流子迁移率为0.6cm^2/V.s;器件性能指标已经达到目前国际上文献报道的最好水平。     

C8 BTBT薄膜结晶形貌及OTFT器件性能研究

以p型共轭有机小分子2,7二辛基[1]苯并噻吩并[3,2‐b]苯并噻吩(C8‐BTBT)作为底栅顶接触有机薄膜晶体管(OTFT)的有源层,采用浸渍提拉法、喷墨打印法和真空蒸镀法三种制备工艺,探究半导体薄膜载流子迁移率与结晶形貌的关系,发现不同工艺下有机小分子呈现出不同的生长行为和结晶情况,在很大程度上决定了OTFT器件性能的优劣;此外,通过XRD分析研究了退火处理对C8‐BTBT结晶的影响。结果表明,真空蒸镀制备的薄膜具有更高的结晶度、衬底覆盖率高,并且呈现出SK(Stranski‐Krastanov)模式的结晶生长特征,相应器件中陷阱密度最低,迁移率高达5.44 cm^2·V^-1·s^-1,开关比超过106;且退火处理会严重破坏C8‐BTBT薄膜的结晶。因此,控制半导体层的生长行为,提升半导体层的覆盖率和结晶度是制备高性能共轭小分子OTFT器件的有效途径。     

聚合物薄膜晶体管的制备及性能

以硅材料衬底作栅电极,在衬底上依次制备二氧化硅栅介质层、聚合物MEH-PPV薄膜半导体层和金源、漏电极,成功地得到了聚合物薄膜晶体管.器件的制备和测试都是在空气环境中完成.该薄膜晶体管呈现出较好的场效应晶体管饱和特性,器件的载流子迁移率为5.0×10-5 cm2/(V·s),开关电流比大于2×103.通过在氮气氛下对聚合物薄膜进行退火处理以及聚合物薄膜沉膜前对二氧化硅表面修饰可以适当地提高器件的载流子迁移率.     

有机半导体在非对称金-石墨烯电极上的取向生长

为了实现在微尺度范围内有机半导体的取向生长,提出了一种基于不对称金-石墨烯电极的底接触有机薄膜晶体管器件结构。半导体前驱体溶液在不同衬底上表现出的不同接触角将打破液体/空气界面处的表面张力与表面能的总体平衡,形成马兰戈尼流并促使溶液在低润湿性的石墨烯电极表面的接触线快速后退。实验结果表明,基于这种不对称电极制备的底接触有机薄膜晶体管(OTFT)阵列的平均迁移率显著提升,达到常规对称结构器件的2倍,同时器件迁移率的相对标准差从53%下降到33%。该不对称器件结构实现了半导体薄膜在器件沟道处的取向生长,从而提高了器件迁移率与均匀性。     

磁控溅射法制备高性能ZnO薄膜晶体管

研究了磁控溅射法制备的ZnO薄膜晶体管(TFT)。以NH3处理的热生长SiO2作为绝缘层,控制好Ar-O2比等条件溅射合适厚度的ZnO作为器件的有源层。实验表明,与普通条件下热生长的SiO2绝缘层硅片相比,NH3处理的高性能SiO2绝缘层Si片器件的载流子迁移率至少要高1个数量级以上;溅射条件在Ar-O2比25∶1情况下制作的器件性能最好;ZnO薄膜厚度也对ZnO-TFT性能有很大的影响。实验中,采用了4种膜厚,测试表明,其中25nm厚的ZnO薄膜迁移率最大。     

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-