离子注入硅快速退火合成Y硅化物的特性

用金属蒸发真空弧离子源注入机将Y离子注入硅,制备出特性良好的硅化物.用掠角沟道技术和透射电子显微镜分析了这种硅化物的结构.用束流密度为25μA/cm2的Y注入硅可形成三层结构的硅化钇.硅化钇层的厚度大约为60-80nm.其缺陷密度Nd和薄层电阻Rs随束流密度的增加而下降.快速退火后,Nd和Rs都明显下降.Rs从54Ω/□下降到14Ω/□.最小电阻率为84μΩ·cm.这说明快速退火可以改善硅化钇的电特性.X射线衍射分析表明YSi和YSi2硅化物已经形成.掠角沟道技术有益于研究薄层硅化物的原子深度分布和品格缺陷密度分布.     

离子注入硅快速退火合成Y硅化物的特性

用金属蒸发真空弧离子源注入机将 Y离子注入硅 ,制备出特性良好的硅化物。用掠角沟道技术和透射电子显微镜分析了这种硅化物的结构。用束流密度为 2 5μA/ cm2的 Y注入硅可形成三层结构的硅化钇。硅化钇层的厚度大约为 60— 80 nm.其缺陷密度 Nd 和薄层电阻 Rs随束流密度的增加而下降。快速退火后 ,Nd和 Rs都明显下降。Rs从 54Ω/□下降到 1 4Ω/□。最小电阻率为 84μΩ·cm.这说明快速退火可以改善硅化钇的电特性。X射线衍射分析表明 YSi和 YSi2 硅化物已经形成。掠角沟道技术有益于研究薄层硅化物的原子深度分布和晶格缺陷密度分布     

超薄SOI应用SALICIDE技术的薄膜厚度优化研究

在ＳＯＩ材料上采用钴自对准硅化物技术，研究了减薄后的ＳＯＩ上钴溅射厚度的优化问题，着重分析了在硅膜厚度一定时钴膜厚度改变、钴膜厚度不变而硅膜厚度变化对硅化物形成后薄层电阻的影响。实验表明，采用Ｔｃｏ：Ｔｓｉ≈１：３．６的近似方法优化钴度膜厚度，会得到薄层电阻最低的硅化接触，改善其接触特性。     

钛离子注入硅薄层硅化物结构和特性

用大束流密度的钛金属离子注入硅,能够直接合成性能良好的薄层硅化物,随束流密度的增加,硅化钛生长,薄层硅化物的薄层电阻（Ｒｓ） 明显下降,当束流密度（Ｊ）为０－７５Ａ／ｍ２ 时,Ｒｓ 达到最小值１６Ω／□,电阻率达到０－６４μΩ·ｍ 。经过１０５０ ℃快速退火２０ｓ 后,Ｒｓ 可下降到２－２Ω／ □,说明退火可进一步改善硅化钛的质量。扫描电子显微镜观察表明,枝状连续的硅化物已经形成。Ｘ衍射分析表明,注入层中形成了ＴｉＳｉ和ＴｉＳｉ２ 。背散射分析表明,其薄层厚度为８０ｎｍ 。利用ＭＥＶＶＡ金属离子注入,可获得直径达到Φ５００ｍ ｍ 注入斑点。     

聚焦离子束选择形成金属硅化物微细图形

用聚焦离子束混合技术选择形成了线宽1μm的金属硅化物微细图形。实验表明镍硅化物主要是由在离子作用下引起的硅原子向金属膜的输运过程形成的,线条的高度随离子剂量的平方根线性增加,适当的后退火过程将大大降低离子束混合形成镍硅化物的电阻率、而达到固相反应形成的镍硅化物相同的水平。     

钒离子注入硅合成硅化钒薄层

用大束流密度的钒金属离子注入硅，能够直接合成性能良好的薄层硅化物，随束流密度的增加，硅化钒相生长，薄层硅化物的方块电阻Ｒｓ明显下降吵流密度为２５μＡ／ｃｍ＾２时，Ｒｓ达到最小值２２Ω／□，说明连续的硅化物已经形成。Ｘ衍射分析表明，注入层中形成了Ｖ３Ｓｉ、Ｖ５Ｓｉ３、Ｖ３Ｓｉ５和ＶＳｉ２四种硅化钒。经过退炎后，Ｒｓ明显地下降，Ｒｓ最大可降到９Ω／□，电阻主可小到７２μΩｍ，说明硅化钒薄层质量得到了进     

一种贱金属玻璃釉电阻浆料

本文主要根据玻璃釉电阻器和电位器所使用的电阻浆料当前存在的问题,如贵金属价高、难免除有害作业、部分性能不稳定等,为寻求成本低、质量好、能适合大生产的电阻浆料,特推荐一种国外采用混合硅化物(硅化镁、二硅化钼、二硅化钽等)加氧化铝配制成的贱金属玻璃釉电阻浆料,介绍其制作工艺与提高性能的方法。     

La,Ce及Nd稀土金属硅化物的生成

用AES,X-射线衍射和RBS等方法分析研究了热反应与离子束混合La,Ce及Nd稀土金属膜和硅反应生成硅化物的物理过程。实验表明:不同的生成条件如热反应温度或离子束混合的剂量能生成富金属硅化物,单硅化物和二硅化物,但最终稳定相都是二硅化物LaSi_2,CeSi_2和NdSi_2。氧的沾污不但影响生成的硅化物相和质量,甚至阻止硅化物的生成。镀膜时的衬底温度和防止氧化的保护层对硅化物薄膜的质量,平整度,均匀性等都有明显的影响。     

用离子束混合形成硅化钛

我们用一种新方法在硅上形成硅化物,硅片上溅射一层600 A的钛膜,在室温下用400keV4×10~(15)Xe~(++)/cm~2,1×10~(16)Xe~(++)/cm~2辐照,利用离子来混合效应形成1000A硅化钛膜.用MeV He 离子背散射方法研究了硅化钛组成和厚度并讨论了形成机制.     

固相反应形成硅化钛薄膜方法及特性研究

本工作研究了固相反应形成硅化钛薄膜的方法及特性.在Ti/Si热处理过程中,氧沾污是一个影响硅化物形成及特性的重要因素.本工作提出了用表面覆盖层抑制氧沾污以形成优良硅化钛薄膜的方法,同时试验了用快速退火技术形成硅化钛的工艺.本文报道和讨论了利用这两种方法形成硅化钛薄膜的实验结果.实验表明,利用这两种方法在适当温度下热处理后能得到电导性能良好的TiSi_2薄膜,而在较低温度下只有富钛的中间相生成.X射线衍射谱给出了高温下明显的择优晶向生长现象.俄歇深度分布表明薄膜中的氧在高温热处理过程中会进行再分布.覆盖层具有阻挡氧原子进入薄膜的效果,并且在晶体的择优晶向生长和氧的再分布效应中起着重要作用.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.