ECR-PECVD方法低温制备多晶硅薄膜

采用ECR-PECVD低温沉积方法,以质量分数为5%的SiH4(配Ar气,SiH4:Ar=1:19)和H2为反应气体,在普通玻璃和单晶硅片衬底上直接沉积多晶硅薄膜,以期寻找到适合大规模工业化生产的方法.当衬底温度为500℃时,即能沉积高质量的多晶硅薄膜.沉积前,H2等离子体的清洗时间和流量对多晶薄膜的质量有较大的影响.通过与其他反应气体相比较,我们制备的多晶硅薄膜不含杂质.     

LIVCD法制备纳米氮化硅粉末工艺参数对粉体特征影响的研究

激光诱导气相沉积法是制备纳米氮化硅粉末的主要方法之一。在制备纳米粉体过程中，各工艺参数的变化对粉体特征有很大的影响。在激光制Si3N4纳米粉中基本的运行参数有：激光强度(I)，反应池压力(P)，反应火焰温度(T)，反应气体配比(ΦSiH4/ΦNH3)，反应气体流速(V)等。通过实验研究了各个工艺参数对粉体特征的影响并分析了其影响的原因。     

H3O+(H2O)n(n=0～4)与甲醇、乙醇反应的实验研究

在流动余辉质谱装置上，利用He的空心阴极放电产物与H2O反应制备了反应物离子H3O (H2O)n(n=0～4)，并观察了H3O (H2O)n(n=0～4)与CH3OH、C2H5OH反应的产物离子，对它们进行了归属，分析了各种产物离子形成的离子-分子反应机制。     

用Cat-CVD方法制备多晶硅薄膜及结构分析

以金属钨为催化热丝,采用热丝催化化学气相沉积,在300℃的玻璃衬底上沉积多晶硅薄膜。研究了H2稀释率、钨丝与衬底间的距离和反应室气体压力等沉积参数对制备多晶硅薄膜的影响,并通过XRD谱分析,确定了本实验系统的最佳多晶硅成膜条件:FR(SiH4)=5mL/min,FR(H2)=70mL/min,P=50Pa,L衬底与钨丝=7.5cm,T=30min,t衬底=300℃,特征峰在(111)面上。在接触式膜厚仪测量的基础上,计算出薄膜生长速率为0.6nm/s。对最佳成膜条件下制备的多晶硅薄膜进行刻蚀,形成不同的厚度,以便进行逐层分析。采用XRD和SEM方法对不同厚度的薄膜测试发现,随着薄膜厚度的减小,(111)面的XRD特征峰强度逐渐下降,(111)面上的晶粒尺寸基本没有变化,都是50nm左右。根据测试结果分析了薄膜的生长机制,提出了薄膜生长是分步成核,成核后沿(111)面纵向生长的观点。认为反应基元首先随机吸附在衬底上,在H原子的作用下在一些位置上成核,而在其他位置形成非晶相。已形成的晶核逐渐长大并沿(111)面纵向生长;已形成的非晶相也在生长,但上面不断有晶核形成。当薄膜达到一定厚度,非晶相表面完全被晶核占据,整个薄膜表面成为多晶相,此后整个薄膜处于沿(111)面的纵向生长阶段,直至反应结束,完整的晶粒结构呈柱状。     

氢原子在Cat-CVD法制备多晶硅薄膜中的作用

采用钨丝催化化学气相沉积(Cat—CVD)方法制备多晶硅(p-Si)薄膜,研究氢气稀释率(FR(H2)／(FR(H2) FR(SiH4))对制备多晶硅薄膜的影响。XRD和喇曼光谱分析分别显示(111)面取向的多晶硅峰及喇曼频移为520cm^-1多晶硅峰的强度随氢气稀释率的增加而增强,由喇曼光谱计算的结晶度也有同样的趋势。通过分析测试结果得出,氢原子以表面脱氢、刻蚀弱的Si—Si键．及进入晶格内部进行深度脱氢等方式改善薄膜材料的结晶度。     

采用微分电导法(R_□)评估POLY/SIS/Si界面状况

提出一种采用微分电导法 (R□ )分别检测实验样品和陪测样品的 R□ ,同时引入 α和 αn 因子分别评估自掺杂多晶硅生长前 Si表面清洗状况 (SIS层厚度 )和自掺杂多晶硅生长后退火或后续高温多晶硅杂质载流子退火特性以及杂质在 POL Y/SIS/Si界面流动情况 .通过实际检测发现这种方法可以定性判断 SIS厚薄和了解自掺杂多晶硅生长后退火或后续高温多晶硅杂质载流子退火特性以及可以半定量估算出自掺杂多晶硅杂质流向 N-层或N+ 层流向自掺杂多晶硅层的杂质总量     

采用微分电导法(R□)评估POLY/SIS/Si界面状况

提出一种采用微分电导法(R□)分别检测实验样品和陪测样品的R□,同时引入α和αn因子分别评估自掺杂多晶硅生长前Si表面清洗状况(SIS层厚度)和自掺杂多晶硅生长后退火或后续高温多晶硅杂质载流子退火特性以及杂质在POLY/SIS/Si界面流动情况.通过实际检测发现这种方法可以定性判断SIS厚薄和了解自掺杂多晶硅生长后退火或后续高温多晶硅杂质载流子退火特性以及可以半定量估算出自掺杂多晶硅杂质流向N-层或N+层流向自掺杂多晶硅层的杂质总量.     

^3He—Ar—Xe核抽运激光腔内能量沉积的蒙特卡罗法研究

本研究的激光介质是3He-Ar-Xe混合气体,属于容积式抽运源模式,利用3He在中子的作用下发生核反应,反应产物离子带着核反应能在气体体系中与激光介质碰撞,把能量传输给激光介质,使Xe的5d[3/2]1能级上的粒子数反转,抽运产生波长为1.73 μm的激光.在核抽运激光器中,3He在中子场中发生的反应如式(1).3He+n1H+3H+0.76 MeV(1) 利用蒙特卡罗方法编制了能量沉积计算程序EDL.利用该软件,研究了激光介质压力对能量沉积的影响,得其表达式β=100-(A1·e-D/t1+A2·e-D/t2)(2) 式中β为能量沉积效率(%),A1、A2、t1和t2为能量沉积函数的参数.理论模拟结果表明,能量沉积效率函数参数A1与压力无关,其它参数都随压力而变化.随着气体总压力的增大,能量沉积效率β也增大. 如果抽运腔内3He分压为PHe,则抽运腔内单位体积内的能量沉积与3He分压PHe(单位Pa)、中子注量率φ (单位n·s-1·cm-2)、反应截面σ(单位cm2)、腔内能量沉积效率β之间的函数关系式ρ=32.41×PHe×σ×φ×β(3) 式中ρ为抽运腔内单位体积的能量沉积,单位为W/cm3.如果考虑3He对中子的自屏蔽效应,则式(3)中的中子注量率φ是随PHe变化的函数.文章最后对核抽运激光输出的稳定性及激光输出功率进行了讨论(OA11)     

低温多晶硅新技术

日立公司为了利用低温多晶硅ＴＦＴ技术实现系统处理芯片集成到ＴＦＴ ＬＣＤ屏上 ,开发了新的激光退火技术。由于准分子激光退火技术熔融硅冷却时间太短 (约 10 0ｎｓ) ,其结果晶粒小、多晶硅迁移率为 10 0～ 2 0 0ｃｍ2 /Ｖ·ｓ,不能满足系统处理芯片集成到ＴＦＴ ＬＣＤ屏上的多晶硅迁移率的要求 (应满足多晶硅迁移率高于 4 0 0ｃｍ2 /Ｖ·ｓ)。日立公司利用Ｎｄ∶ＹＶＯ4固体激光器可以控制脉宽和间隙 ,从而得到大晶粒多晶硅 ,其多晶硅迁移率为 4 80ｃｍ2 /Ｖ·ｓ,最大迁移率可达 6 70ｃｍ2 /Ｖ·ｓ,为系统集成创造了条件。低温多晶硅新…     

低温多晶硅新技术

日立公司为了利用低温多晶硅TFT技术实现系统处理芯片集成到TFT LCD屏上 ,开发了新的激光退火技术。由于准分子激光退火技术熔融硅冷却时间太短 (约 1 0 0ns) ,结果导致晶粒小、多晶硅迁移率低 (为 1 0 0～ 2 0 0cm2 /V·s) ,不能满足系统处理芯片集成到TFT LCD屏上的多晶硅迁移率要求 (多晶硅迁移率应高于 40 0cm2 /V·s)。该公司利用Nd∶YV0 4 固体激光器以控制脉宽和间隙 ,从而得到大晶粒多晶硅 ,其多晶硅迁移率为480cm2 /V·s ,最大迁移率可达 670cm2 /V·s,为系统集成创造了条件低温多晶硅新技术…     

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-