Si1-xGex/Si应变材料的生长及热稳定性研究

利用分子束外延（MBE）技术生长了Ge组份为0.1-0.46的Si1-xGex外延层。X射线衍射线测试表明，SiGe/Si异质结材料具有良好的结晶质量和陡峭界面，其它参数与可准确控制。通过X射线双晶衍射摆曲线方法，研究了经700℃、800℃和900℃退火后应变SiGe/Si异质结材料的热稳定性。结果表明，随着退火温度的提高，应变层垂直应变逐渐减小，并发生了应变弛豫，导致晶体质量退化；且Ge组分越小，Si1-xGex应变结构的热稳定性越好；室温下长时间存放的应变材料性能稳定。     

低温硅结合离子注入技术制备应变Si材料

为制作应变硅MOS器件,给出了一种制备具有高表面质量和超薄SiGe虚拟衬底应变Si材料的方法。通过在Si缓冲层与赝晶Si0.8Ge0.2之间设置低温硅（LT-Si）层,由于失配位错限制在LT-Si层中且抑制线位错穿透到Si0.8Ge0.2层,使表面粗糙度均方根值（RMS）为1.02nm,缺陷密度系106cm-2。又经过P+注入和快速热退火,使Si0.8Ge0.2层的应变弛豫度从85.09%增加到96.41%,且弛豫更加均匀。同时,RMS（1.1nm）改变较小,缺陷密度基本没变。由实验结果可见,采用LT-Si层与离子注入相结合的方法,可以制备出满足高性能器件要求的具有高弛豫度、超薄SiGe虚拟衬底的高质量应变Si材料。     

应变硅薄膜的厚度对材料迁移率的影响

用化学气相沉积方法在SiC/Si上外延生长了应变硅薄膜.扫描电子显微镜方法显示所得样品具有明显的Si/SiC/Si三层结构,喇曼散射光谱和X射线衍射测量结果表明外延的Si薄膜存在应变.Hall效应测量证明相比于相同浓度的体Si材料应变Si薄膜具有较高的霍尔迁移率;但随着应变硅层厚度的增加,霍尔迁移率下降,这应与薄膜中应变减小和失配位错有关.     

应变硅薄膜的厚度对材料迁移率的影响

用化学气相沉积方法在SiC/Si上外延生长了应变硅薄膜.扫描电子显微镜方法显示所得样品具有明显的Si/SiC/Si三层结构,喇曼散射光谱和X射线衍射测量结果表明外延的Si薄膜存在应变.Hall效应测量证明相比于相同浓度的体Si材料应变Si薄膜具有较高的霍尔迁移率;但随着应变硅层厚度的增加,霍尔迁移率下降,这应与薄膜中应变减小和失配位错有关.     

应变硅结构的高分辨X射线衍射及其图谱分析

运用高分辨X射线双晶衍射（DCD) 、三轴晶衍射（TAD）和TAD图谱对绝缘体上Si/SiGe/Si异质结构进行表征. 利用TAD结合DCD (TAD-DCD）对称和非对称衍射测定了体Si衬底和外延层以及外延层之间的取向关系、SiGe外延层的Ge含量及其弛豫度等异质外延生长的重要参数. TAD倒易空间图谱能够给出全面的晶体结构信息. 高分辨率TAD倒易空间图谱可实现对应变Si层应变量的测定.     

Si间隔层对利用低温Si缓冲层生长高弛豫SiGe层的影响

利用低温生长Si缓冲层与Si间隔层相结合的方法生长高弛豫SiGe层,研究了Si间隔层在其中的作用. 利用化学腐蚀和光学显微镜，观察了不同外延层厚度处位错的腐蚀图样. 研究了不同温度下生长的Si间隔层对SiGe外延层中位错形成、传播及其对应变弛豫的影响. 结果表明Si间隔层的引入，显著改变了外延层中位错的形成和传播，进而使得样品表面形貌也呈现出较大的差异.     

在Si(211)衬底上分子束外延CdTe的晶格应变

文章利用高分辨率X射线衍射技术对分子束外延CdTe（211）B/Si（211）材料的CdTe外延薄膜进行了倒易点二维扫描,并通过获得的对称衍射面和非对称衍射面的倒易空间图,对CdTe外延层的剪切应变和正应变状况进行了分析.研究发现,对于CdTe/Si结构,随着CdTe厚度的增加,[1-1-1]、[01-1]两个方向的剪切角γ[1-1-1]和λ[01-1]都有变小的趋势,且γ[1-1-1]的大小约为γ[01-1]的两倍;对于CdTe/ZnTe/Si,ZnTe缓冲层的引入可以有效地降低CdTe层的剪切应变.CdTe层的正应变表现为张应变,主要来源于CdTe和Si的热膨胀系数存在差异,而在从生长温度280℃降至室温20℃的过程产生的热应变.     

一种新颖的应变Si沟道 pMOSFET制作技术

在应变Si沟道异质结场效应晶体管(HFET)制作过程中,引入分子束外延(MBE)低温Si(LT-Si)技术,大大减少了弛豫SiGe层所需的厚度.TEM结果表明,应变Si层线位错密度低于106cm-2.原子力显微镜(AFM)测试表明,其表面均方粗糙度小于1.02nm.器件测试结果表明,与相同条件下的体Si pMOSFET相比,空穴迁移率提高了25%.     

一种新颖的应变Si沟道 pMOSFET制作技术

在应变Si沟道异质结场效应晶体管(HFET)制作过程中,引入分子束外延(MBE)低温Si(LT-Si)技术,大大减少了弛豫SiGe层所需的厚度.TEM结果表明,应变Si层线位错密度低于106cm-2.原子力显微镜(AFM)测试表明,其表面均方粗糙度小于1.02nm.器件测试结果表明,与相同条件下的体Si pMOSFET相比,空穴迁移率提高了25%.     

应变Si/(111)Si1-xGex带边能级计算

采用结合形变势理论的k.p微扰法计算了（111）面弛豫Si1-xGex衬底生长双轴应变Si材料的带边能级。结果表明,应变Si/(111)Si1-xGex材料导带简并度与弛豫Si材料相同,价带带边简并度在应力的作用下部分消除,导带和价带带边能级均随着Ge组份（x）的增加而增加。此外,本文还给出了禁带宽度、价带劈裂能随Ge组份（x）的函数关系。以上量化结论可为Si基应变器件设计提供有价值的参考。     

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.     

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.     

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.     

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.